Cranial 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. A cranial protection cell for receiving a user's head comprising: (a) an outer rigid shell; (b) a double layer of impact absorbing material coating the inside of said rigid outer shell, comprising a first outer layer located next to said shell and a second innermost layer located next to the first outer layer, the first outer layer be disposed between the outer rigid shell and the second innermost layer; (c) said first outer layer being provided with a plurality of cavities; (d) said second innermost layer formed of a viscoelastic material and is provided with a plurality of viscoelastic protrusions that fit into the plurality of cavities provided in said first outer layer, said protrusions being elastically deformable under mechanical stress; (e) said first outer layer having greater rigidity and lower density than said second innermost layer and greater thickness than said second innermost layer; (f) a visor, and wherein said outer rigid shell includes a front aperture, the visor being embedded in a front aperture of said shell when closed; and (g) at least one right side supporting rod, and at least one left side supporting rod, wherein each of said at least one right side supporting rod and said at least one left side supporting rod includes a proximal end and a distal end, said visor having a right side and a left side attached respectively to said distal ends of said at least one right side supporting rod and said at least one left side supporting rod, respectively, each said proximal end including an integral pin-shaped axis, wherein said shell includes a through slit on each of said right side and said left side of the shell, each said through slit having a rear end including a first flare and a front end including a second flare, respectively, whereby said pin-shaped axes are received as a non-permanent fitting.

2. The cranial protection cell according to claim 1, wherein said first outer layer is comprised 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.

3. The cranial protection cell according to claim 1, wherein said second innermost layer consists of open cell viscoelastic foam, with a density between 50 and 95 kg/m.sup.3 and indenting force (40%) between 80N and 150N.

4. The cranial protection cell according to claim 1 including a chin area configured to be disposed proximal to a jaw of the head of the user, wherein the impact absorbent material comprises supporting pads in the chin area, adapted to be at a front part of the jaw, the support pads including a double layer of impact absorbing material.

5. The cranial protection cell according to claim 1, further comprising impact absorbent material supporting pads positioned within the rigid shell such that the impact absorbent material supporting pads are adapted to be disposed at face maxillary regions of the user's head when the cranial protection cell receives the user's head, the impact absorbent material supporting pads including a double layer of impact absorbing material.

6. The cranial protection cell according to claim 1, further comprising impact absorbent material supporting pads positioned within the rigid shell such that the impact absorbent material supporting pads are adapted to be disposed at mastoid regions of the user's head when the cranial protection cell receives the user's head, the impact absorbent material supporting pads including a double layer of impact absorbing material.

7. The cranial protection cell according to claim 1, further including a right side external drive button located on a right side of the shell, a left side external drive button located on a left side of the shell, wherein the pin-shaped axis included in the proximal end of the at least one right side supporting rod is associated with said right side external drive button and the pin-shaped axis included in the proximal end of the at least one left side supporting rod is associated with said left side external drive button.

8. The cranial protection cell according to claim 1, wherein the opening of the visor is performed in two steps, the first step comprising disengagement of the visor from the front aperture through a forward translational movement, by means of the forward movement of said pin-shaped axis from said first flare towards said second flare of said through slit, the second step of opening of the visor comprising the upward rotation of the support rod about said pin-shaped axis after said pin-shaped axis is fitted into said second flare.

9. The cranial protection cell according to claim 1, further comprising a removable chin guard and respective locking mechanisms located on either side of the outer rigid shell.

10. The cranial protection cell according to claim 9, further comprising a retaining member attached to the chin guard, the retaining member including teeth, and wherein each locking mechanism comprises an outer drive button and a swing lock, the swing lock including first and second ends, the outer drive button being coupled to the first end of the swing lock, the second end of the swing lock including a retainer claw fitted into the teeth of the retaining member attached to the chin guard.

11. A cranial protection cell for receiving a user's head comprising: (a) an outer rigid shell; (b) a double layer of impact absorbing material coating the inside of said rigid outer shell, comprising a first outer layer located next to said shell and a second innermost layer located next to the first outer layer, the first outer layer be disposed between the outer rigid shell and the second innermost layer; (c) said first outer layer being provided with a plurality of cavities; (d) said second innermost layer formed of a viscoelastic material and is provided with a plurality of viscoelastic protrusions that fit into the plurality of cavities provided in said first outer layer, said protrusions being elastically deformable under mechanical stress; (e) said first outer layer having greater rigidity and lower density than said second innermost layer and greater thickness than said second innermost layer; (f) a removable chin guard and respective locking mechanisms located on either side of the outer rigid shell; (g) a retaining member attached to the chin guard, the retaining member including teeth, and wherein each locking mechanism comprises an outer drive button and a swing lock, the swing lock including first and second ends, the outer drive button being coupled to the first end of the swing lock, the second end of the swing lock including a retainer claw fitted into the teeth of the retaining member attached to the chin guard.

Description

DESCRIPTION OF THE DRAWINGS

(1) Further features 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:

(2) FIG. 1 illustrates, in a simplified way, the shear effect resulting from the application of rotational stress.

(3) 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.

(4) FIG. 3 shows a state-of-the-art helmet fitted with a single layer absorbent material.

(5) 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.

(6) 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.

(7) FIG. 6-a is a schematic perspective view showing the relationship between the layers of impact absorbing material used in the invention.

(8) FIGS. 6-b and 6-c outline the deformation at the interface between the stiffer outer layer and the inner viscoelastic layer upon application of a tangential stress.

(9) FIG. 7 shows, in detail, the provision of the absorptive material pads in the chin guard and in the maxillary region.

(10) FIG. 8 shows, in detail, the provision of the absorptive material pads in the mastoid regions.

(11) FIGS. 9a-9e show in detail the sequence of steps having to do with the handling of the visor and depicting its opening.

(12) FIGS. 10-a, 10-b and 10-c refer to details of the removable chin guard and its retention mechanism, according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(13) 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.

(14) When an impact occurs, the user's 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.

(15) 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, it reduces points of tension in the user's 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 element. It has a role similar to that of the cerebrospinal fluid in the central nervous system.

(16) 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 material's indentation strength at 40% 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.

(17) As shown by FIG. 6-A, said layers interdigitate 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 similar mechanical behavior as defined herein, may even result in the future decrease of this thickness.

(18) 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 provided in the first layer 21, a plurality of protrusions 23 corresponding thereto are provided in the second layer 22, said protrusions being positioned coincidently with said cavities, in which they fit cooperatively and complementarily. This figure further shows a comfort fabric 26 between the second layer 22 and the user's head 25, and the shell 20 to which the double layer of impact absorbing material is attached.

(19) 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.

(20) As shown in FIG. 6-C, part of the tangential forces acting on the shell 20 are dissipated by the deformation of the protrusions 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 layer and then the semi-rigid layer, 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.

(21) FIG. 7 is an illustrative view of the absorbent material supporting pads 32 in the chin guard 31, which surrounds the mental 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.

(22) FIG. 7 further shows one of the external drive buttons 35 of the visor lock, as will be described in connection with FIG. 9.

(23) As shown in FIG. 8, the invention further provides absorptive material support pads 36 in the mastoid regions, thereby creating a third retention point, in addition to the mental region and jugular strap.

(24) The set of FIGS. 9-a . . . 9-e refers to the handling of the visor of the cranial protection cell (CPC) 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 subassembly mechanism, as will be described below.

(25) FIG. 9-b is a partial external view of the CPC showing one of the drive buttons 35 of the visor subassembly, located on the side of the shell, there being a similar, symmetrically disposed button on the opposite side of the shell.

(26) According to the detailed internal view of FIG. 9-c, said button is internally associated with a pin-shaped axis 40 around which the visor subassembly rotates when it is lifted during the opening procedure. As shown, the visor 37 is rigidly attached to the distal end 38a of a rod 38 whose proximal end is integral with said pin-shaped axis.

(27) 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 with enlargements, i.e., flares into which said pin-shaped axis fits. In the normally closed position, shown in FIG. 9-c, the pin-shaped axis 40 fits into 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.

(28) To open the visor, the buttons 35 disengage each of the pin-shaped axis 40 from said first flare, allowing the subassembly—comprising pin-shaped axes 40, rods 38 and visor 37—to be pushed horizontally forward to the position shown in FIG. 9-d, where pin-shaped axes 40′ fit into the second—forward—flare 39b of each of said through slits 39. As shown in the figure, the visor is now in an advanced position relative to the front of the shell.

(29) To complete the opening procedure, the rods 38 rotate about the fulcrums that correspond to pin-shaped axes 40′, as indicated in FIG. 9-E, this rotation being limited by the contact of restraining means 38a at the distal ends of the rods 38′ with the upper edge 42 of the shell aperture 55.

(30) 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 shows 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.

(31) FIG. 10-b is a detailed view corresponding to the B-B cross-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, that is attached to the groove 54 and the main shell 11 of the CPC.

(32) 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.

(33) 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: face protective structure, protecting against frontal impacts; reduction of the risk of Torque and Diffuse Axonal Injury reduced weight, around 1 kg, with more comfort and less aerodynamic drag; visor fitting system, increased optical efficiency and removable chin guard; absorptive material in the mastoid regions; better CPC retention in the user's head; smooth shell without protrusions, avoiding the head locking against some external obstacle, which contributes to reduce or prevent torque.

(34) Thus, the Cranial Protection Cell of the invention embodies a radically innovative concept when compared to known helmets, overcoming the previous technique from a functional point of view, extending in a significant and scientific way the protection of the skull and, consequently, of the brain.