This application claims priority from U.S. Ser. No. 13/617,663 filed on Sep. 14, 2012 and from U.S. Ser. No. 13/670,961 filed on Nov. 7, 2012 which are hereby incorporated by reference in their entirety herein.
1. Field
The present disclosure relates to helmets. More particularly, the present disclosure relates to protective helmets having enhanced protective performance characteristics. The present disclosure has application to football helmets, ice-hockey helmets, baseball helmets, motorcycle helmets, riot helmets, military helmets and other similar helmets, although it is not limited thereto.
2. State of the Art
Head trauma resulting from sports and other activities is a common occurrence. Generally, head trauma occurs when an object impacts the head, thereby transferring energy to the head. The most common head trauma resulting from sports is a concussion, which occurs when the brain bangs inside the skull and is bruised. To reduce the incidence of concussion, it is common practice to wear a protective helmet. Protective helmets are ostensibly designed to deflect and absorb energy transmitted by impact to the helmet, thereby diminishing the risk of head and brain injury resulting from the impact.
Protective athletic helmets have been worn for almost a century, and have evolved from sewn leather, to helmets having molded plastic outer shells with suspension webbing or other head fitting structures such as foam pads, air bladders, or padded molding on their interior. Despite the evolution of the protective helmets, the reported rate of concussions has been increasing amongst student and professional athletes in many sports. While some experts have attributed this increase to better reporting and diagnosis, other experts have attributed the increase to increased forces generated as competitive athletes continue to increase in size (mass) and increase their ability to accelerate.
What has not been necessarily considered is that the increase in concussions actually may be attributable to the structure of the evolved protective helmets. In particular, the molded hard plastic helmets have not been shown to absorb energy effectively as they tend to transmit pressure waves, and in helmet to helmet contact situations may actually add to trauma. In addition, the evolved protective helmets have a considerable weight that may lead to other injuries.
It is also known that head trauma resulting in traumatic brain injury (TBI) has become a common occurrence in the military. A common cause of TBI is damage caused by explosive devices such as improvised explosive devices (IEDs).
TBI injuries fall into several categories that may have different symptoms. Mild TBI (MTBI), commonly referred to as a concussion, is a brief loss of consciousness or disorientation ranging up to thirty minutes. Although brain damage may not be visible on an MRI or CAT scan, common symptoms of MTBI include headache, confusion, lightheadedness, dizziness, blurred vision, ringing in the ears, fatigue or lethargy, behavioral or mood changes, and trouble with memory, concentration or attention. Severe traumatic brain injury is associated with loss of consciousness for over thirty minutes or amnesia. Symptoms of severe TBI include all those of MTBI as well as headaches that increase in severity or do not abate, repeated vomiting or nausea, convulsions or seizures, dilation of the eye pupils, slurred speech, weakness or numbness in the extremities, loss of coordination, and increased confusion or agitation. TBI injuries can cause lasting physical and cognitive damage.
Presently, the U.S. army utilizes the Advanced Combat Helmet (ACH) that incorporates ballistic fiber such as KEVLAR (a trademark of DuPont of Wilmington, Del.), TWARON (a trademark of Teijin Twaron, B.V. of the Netherlands), or ultra-high-molecular-weight polyethylene (UHMWPE). The ACH has a suspension system including a rear suspension system to which a ballistic “nape pad” is attached. The nape pad is intended to reduce solider deaths from shrapnel wounds to the neck and lower head.
Despite the introduction of the ACH, TBI injuries continue to be a major cause of concern.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
A protective helmet includes a multilayered system including a cushioning outer shell, a hard inner structure, a cushioning spacer layer between the cushioning outer shell and the hard inner structure, with the cushioning spacer layer arranged relative to the hard inner structure to redirect energy transmitted from the cushioning outer shell along a circuitous path to air and to the hard inner structure, and plurality of innermost cushioning pads coupled to the inside of the hard inner structure.
In one embodiment, the cushioning outer shell is covered by a flexible thin cover. The flexible thin cover may be a fabric, film, foil, or other cover. The flexible thin cover may be cosmetic and may provide a surface for printing graphics. The flexible thin cover may also protect the cushioning outer shell from damage.
In one embodiment, the hard inner structure is an integral structure that includes a plurality of lateral and horizontal frame members which define a plurality of spaces. One function of the hard inner structure is to provide a structural integrity for the helmet. In one embodiment, the spaces between the members are maximized in size to reduce the weight of the structure while still maintaining structural integrity.
In one embodiment, the cushioning spacer layer includes a plurality of elements glued or otherwise attached to the cushioning outer shell and to the hard inner structure. In another embodiment, the cushioning spacer layer comprises a single member defining a plurality of spaces. The cushioning spacer layer elements or member may include a plurality of layers of different densities.
In one embodiment the cushioning spacer layer member or elements at least partially overlie the spaces defined by the hard inner structure.
In one embodiment one or more of cushioning layers or elements is formed from a foam material such as an elastomeric, cellular foam material. In another embodiment, one or more of the cushioning layers is made of thermoplastic polyurethane (TPU).
A military helmet includes a multilayered system including a cushioning outer shell, a hard ballistic resistant inner shell, a cushioning spacer layer between the cushioning outer shell and the hard inner shell, with the cushioning spacer layer arranged relative to the hard inner shell to redirect energy transmitted from the cushioning outer shell along a circuitous path to air and to the hard inner shell, and plurality of innermost cushioning pads coupled to the inside of the hard inner shell.
In one aspect, the cushioning outer shell of the military helmet serves the purpose of absorbing or deflecting an acoustic shock wave that can impact the military helmet in advance of the impact of a projectile (e.g., bullet).
In one embodiment, the cushioning outer shell of the military helmet is covered by a flexible thin cover. The flexible thin cover may be a fabric, film, foil, or other cover such as a ballistic nylon (a high denier nylon thread with a dense basket weave) that is used as a cover for the ACH. The flexible thin cover may provide a surface for printing graphics (e.g., camouflage). The flexible thin cover may also protect the cushioning outer shell from damage.
In one embodiment, the hard ballistic resistant inner shell is formed from a ballistic fiber composite material such as KEVLAR.
a is a perspective view of an alternative cushioning spacer layer.
b is a perspective view of an alternative hard inner structure.
a and 7b are bottom and perspective views of an embodiment of a football helmet.
One embodiment of a protective helmet 10 is seen in
In one aspect, the material of the hard inner structure 40 is considerably harder than the material(s) of the cushioning outer shell layer 20 and the cushioning spacer layer 30. In another aspect, the material(s) of the cushioning outer shell layer 20 and the cushioning spacer layer are resilient. In one embodiment, the cushioning spacer layer defines gaps that are non-uniform in shape and/or in size.
With the structure of helmet 10, when the helmet is hit by a projectile, the energy imparted by the projectile to the helmet can take various paths. First, it should be appreciated that the cushioning outer shell 20 will absorb and/or distribute some or all of the energy. The energy may be absorbed by (resilient) deflection of the foam cushioning. If some of the energy passes through the cushioning outer shell 20 it can either pass into the cushioning spacers 30 or into the air between the cushioning spacers. Again, if the energy pass into the cushioning spacers, the energy may be absorbed by (resilient) deflection of the cushioning spacers. Alternatively or in addition, the energy may be absorbed in the air between the cushioning spacers. Energy passing through the cushioning spacer level will reach the hard inner structure 40 or air gaps therein where it can be one or more of reflected, distributed, absorbed or transmitted. Typically, the hard inner structure 40 will not absorb much energy. As a result, the function of the hard inner structure 40 is primarily one of lending structural integrity to the helmet 10. Any energy passing through the hard inner structure or the air gaps therein will be passed to the innermost cushioning pads 50 (also typically resilient) or the air gaps between the pads where the energy again may be absorbed by (resilient) deflection of the cushioning pads 50 or by the air gaps therein. With all of these possible paths, it will be appreciated that the energy imparted by impact to the helmet will be significantly dissipated before reaching the head of the user. In addition, by forcing the energy through a tortuous path due to the use of cushioning and multiple layers with air gaps, the resistance to the energy shock waves by the helmet is increased. In this manner, the incidence of brain concussions of wearers of the helmet 10 can be reduced.
Some of the energy paths through the helmet can be seen by reference to the
It should be appreciated that the described cross-sections give certain energy paths through the helmet 10, but that many other exist, and it is not necessary that all of these paths exist simultaneously in a helmet. In fact, it will be appreciated that energy waves will generally take a path of least resistance through a substance which may not correspond exactly to any of the cross-sections. Because harder substances will generally transmit energy waves more readily than air, the air gaps will cause the energy to travel and spread radially through the cushioning shell 20 and the hard inner structure 40. However, travel through a longer distance in the cushioning shell 20 and the hard inner structure 40 causes further attenuation of the energy.
In one embodiment, the flexible thin cover 15 may be a fabric, film, foil, leather, or other cover. The flexible thin cover may be cosmetic and may provide a surface for printing graphics. The flexible thin cover may also protect the cushioning outer shell from damage. If desired, the flexible thin cover may extend around the periphery of the helmet (as suggested in
In one embodiment the cushioning shell 20 is comprised of foam. The foam may be an elastomeric, cellular (including microcellular) foam or any other desirable foam. In another embodiment, the cushioning shell is comprised of a soft resilient thermoplastic polyurethane (TPU) (i.e., having a Shore hardness considerably below the Shore hardness of the hard inner structure). In another embodiment, the cushioning shell is comprised of open-cell polyurethane. In another embodiment, the cushioning shell is comprised of closed cell polyolefin foam. In another embodiment, the cushioning shell is comprised of polyethylene foam which may be a high or low density polyethylene foam. In one embodiment, the outer surface 22 of the cushioning shell 20 is generally (hemi)-spherical in shape. By way of example and not by way of limitation, the cushioning shell may be between 3 mm and 13 mm thick, although it may be thinner or thicker. By way of example, and not by way of limitation, the cushioning shell may have a density of between 3.4 lbs/ft3 (approximately 0.016 g/cm3) and 25 lbs/ft3 (approximately 0.4 g/cm3), although it may be more dense or less dense.
In one embodiment the cushioning spacer layer 30 comprises a plurality of pads 31. The pads 31 may be circular in shape or may be formed in other shapes. Multiple shapes may be used together. In one embodiment, the spacer layer may include a strip of material 33 (seen in
According to one embodiment, the spacer layer 30 covers approximately fifty percent of the inner surface area of the shell 20. In another embodiment, the spacer layer 30 covers between twenty percent and ninety-five percent of the inner surface area of the shell. The spacer layer 30 should cover sufficient area between the shell 20 and the hard inner structure 40 so that upon most expected impacts to the helmet 10, the shell 20 does not directly come into contact with the hard inner structure 40. Regardless of the material and arrangement of the cushioning spacer layer 30, in one embodiment the cushioning material is affixed to the shell 20 and to the hard inner structure. Affixation can be done with glue, Velcro or any other affixation means.
In one embodiment, the hard inner structure 40 is comprised of a polycarbonate shell. In another embodiment, the hard inner structure 40 is comprised of a different hard plastic such a polypropylene. In another embodiment, the hard inner structure 40 is comprised of ABS resin. In another embodiment, the hard inner structure 40 is made of carbon fiber or fiberglass. In another embodiment, the hard inner structure is made of a polypropylene which is considerably harder than the materials of the cushioning layer 20 and spacer layer 30. Generally, the hardness of the hard inner structure may be characterized by a hardness on the Shore D Durometer scale (typically Shore D 75 and over), whereas generally, the hardness of the materials of the cushioning layer 20 and the spacer layer 30 are characterized by a hardness on the Shore A Durometer scale (typically Shore A 60 and under, and even more typically Shore A 30 and under). In one embodiment, as shown in
In one embodiment, the one or more innermost cushioning pad(s) 50 is comprised of foam. The foam may be an elastomeric, cellular (including microcellular) foam or any other desirable foam. In another embodiment, the cushioning pad(s) 50 is comprised of a soft resilient thermoplastic polyurethane (TPU). In another embodiment, the cushioning pad(s) is comprised of open-cell polyurethane. In another embodiment, the cushioning pad(s) is comprised of closed cell polyolefin foam. In another embodiment, the cushioning pad(s) is comprised of polyethylene foam which may be a high or low density polyethylene foam. In one embodiment the innermost cushioning pad 50 is a single pad defining multiple cut-outs (i.e., the equivalent of multiple connected pads). In another embodiment, a plurality of innermost cushioning pads 50 are provided. Regardless, the single pad with the cut-outs or the multiple pads are arranged in a desired configuration and are affixed to the hard inner structure 40. Affixation can be done with glue, Velcro or any other affixation means. By way of example and not by way of limitation, the innermost cushioning layer may be between 3 mm and 26 mm thick, although it may be thinner or thicker. By way of example, and not by way of limitation, the innermost cushioning pads may have a density of between 3.4 lbs/ft3 (approximately 0.016 g/cm3) and 25 lbs/ft3 (approximately 0.4 g/cm3), although they may be more dense or less dense.
In one embodiment, the innermost cushioning pad(s) 50 is covered by a fabric layer 55 (seen in
Turning to
The helmets previously described may be used as or in conjunction with football helmets, ice-hockey helmets, baseball helmets, motorcycle helmets, riot helmets, and other similar helmets, although they are not limited thereto. Thus, for example, a riot helmet can have a polycarbonate face extending from the front face of the helmet. As seen in
In one embodiment, the football helmet 110 has a thickness of between 20 mm and 50 mm, although it may be thinner or thicker.
One embodiment of a military helmet 210 is seen in
When a projectile is shot at the helmet, before the projectile reaches the helmet, an energy wave hits the helmet. This energy wave can be a significant percentage of the total energy (energy or shock wave energy plus projectile energy) that impacts the helmet. In fact, in some circumstances, it is possible that only a shock wave is received, in which case, the shock wave is 100% of the total energy impacting the helmet. The military helmet 210 is designed to lessen the total energy impact on its user in two separate manners. First, the energy wave can take various paths. For example, it should be appreciated that the cushioning outer shell 220 will absorb and/or distribute some or all of the energy. The energy may be absorbed by deflection of the foam cushioning. If some of the energy passes through the cushioning outer shell 220 it can either pass into the cushioning spacers 230 or into the air between the cushioning spacers. Again, if the energy passes into the cushioning spacers, the energy may be absorbed by deflection of the cushioning spacers. Alternatively or in addition, the energy may be absorbed in the air between the cushioning spacers. Energy passing through the cushioning spacer level will reach the hard inner shell where it can be one or more of reflected, distributed, absorbed or transmitted. Energy passing through the hard inner ballistic-resistant will be passed to the innermost cushioning pads 250 or the air gaps between the pads where the energy again may be absorbed by deflection of the cushioning pads 250 or by the air gaps therein. With all of these possible paths, it will be appreciated that the energy imparted by the energy shock wave will be significantly dissipated before reaching the head of the user. In addition, by forcing the energy wave through a tortuous path due to the use of cushioning and multiple layers with air gaps, the resistance to the energy shock waves by the helmet is increased. In this manner, the incidence of brain concussions of wearers of the military helmet 210 can be reduced.
The military helmet 210 is also adapted to lessen the impact of the projectile itself. In particular, while the cushioning outer shell 220 and the cushioning spacer layer 230 will not appreciably stop the projectile, the hard inner shell 240 formed from a ballistic-resistant material will act to stop the projectile in the manner of the previously described with reference to the Advanced Combat Helmet.
Some of the energy paths through the helmet can be seen by reference to
It should be appreciated that the described cross-sections give certain energy paths through the military helmet 210, but that many other exist, and it is not necessary that all of these paths exist simultaneously in a military helmet. In fact, it will be appreciated that energy waves will generally take a path of least resistance through a substance that may not correspond exactly to any of the cross-sections. Because harder substances will generally transmit energy waves more readily than air, the air gaps will cause the energy to travel and spread radially through the cushioning shell 220 and the hard inner shell 240. However, travel through a longer distance in the cushioning shell 220 and the ballistic-resistant inner shell 240 causes further attenuation of the energy.
In one embodiment, the flexible thin cover 215 may be a fabric, film, foil, or other cover such as a ballistic nylon (a high denier nylon thread with a dense basket weave) that is used as a cover for the ACH. The flexible thin cover may provide a surface for printing graphics, e.g., camouflage (see
In one embodiment the cushioning shell 220 is comprised of foam. The foam may be an elastomeric, cellular (including microcellular) foam or any other desirable foam. In another embodiment, the cushioning shell is comprised of a soft resilient thermoplastic polyurethane (TPU). In another embodiment, the cushioning shell is comprised of open-cell polyurethane. In another embodiment, the cushioning shell is comprised of closed cell polyolefin foam. In another embodiment, the cushioning shell is comprised of polyethylene foam which may be a high or low density polyethylene foam. In all embodiments, the hardness of the cushioning shell is much lower than the hardness of the ballistic-resistant inner shell 240. For example, the hardness of the cushioning shell is typically described by the Shore A Durometer scale (typically Shore A 60 and under, and even more typically Shore A 30 and under), whereas the hardness of the ballistic-resistant inner shell is described by the Shore D Durometer scale.
In one embodiment, the outer surface 222 of the cushioning shell 220 is generally (hemi-)spherical in shape. By way of example and not by way of limitation, the cushioning shell may be between 3 mm and 13 mm thick, although it may be thinner or thicker. By way of example, and not by way of limitation, the cushioning shell may have a density of between 3.4 lbs/ft3 (approximately 0.016 g/cm3) and 25 lbs/ft3 (approximately 0.4 g/cm3), although it may be more dense or less dense.
In one embodiment the cushioning spacer layer 230 comprises a plurality of pads 231. The pads 231 may be circular in shape or may be formed in other shapes. Multiple shapes may be used together. In one embodiment, the spacer layer may include a strip of material 233 (seen in
According to one embodiment, the spacer layer 230 covers approximately fifty percent of the inner surface area of the shell 220. In another embodiment, the spacer layer 230 covers between twenty percent and eighty percent of the inner surface area of the shell. The spacer layer 230 should cover sufficient area between the shell 220 and the hard inner shell 240 so that upon most expected impacts to the helmet 210, the shell 220 does not directly come into contact with the hard inner shell 240. Regardless of the material and arrangement of the cushioning spacer layer 230, in one embodiment the cushioning material is affixed to the shell 220 and to the hard inner structure. Affixation can be done with glue, Velcro or any other affixation means.
In one embodiment, the hard ballistic-resistant inner shell 240 is comprised of a ballistic-resistant fibrous material. In one embodiment the inner shell material comprises a para-aramid synthetic fiber such as KEVLAR (a trademark of DuPont of Wilmington, Del.). In another embodiment the inner shell material comprises TWARON (a trademark of Teijin Twaron, B.V. of the Netherlands). In another embodiment, the inner shell material comprises ultra-high-molecular-weight polyethylene. As previously mentioned, in one embodiment the hard ballistic-resistant shell 240 is affixed to the spacer layer 230. Affixation can be done with glue, Velcro or any other affixation means. By way of example and not by way of limitation, the hard ballistic-resistant shell is between 2 mm and 20 mm thick, although it may be thinner or thicker. As another example, the hard inner ballistic-resistant shell 240 is between 7 mm and 12 mm thick.
In one embodiment, the one or more innermost cushioning pad(s) 250 is comprised of foam. The foam may be an elastomeric, cellular foam or any other desirable foam. In another embodiment, the cushioning pad(s) 250 is comprised of a soft resilient thermoplastic polyurethane (TPU). In another embodiment, the cushioning pad(s) is comprised of open-cell polyurethane. In another embodiment, the cushioning pad(s) is comprised of closed cell polyolefin foam. In another embodiment, the cushioning pad(s) is comprised of polyethylene foam which may be a high or low density polyethylene foam. In all embodiments, the hardness of the material innermost cushioning pad(s) is considerably lower than the hardness of the ballistic-resistant inner shell 240. In one embodiment the innermost cushioning pad 250 is a single pad defining multiple cut-outs (i.e., the equivalent of multiple connected pads). In another embodiment, a plurality of innermost cushioning pads 250 are provided. Regardless, the single pad with the cut-outs or the multiple pads are arranged in a desired configuration and are affixed to the hard inner structure 240. Affixation can be done with glue, Velcro or any other affixation means. By way of example and not by way of limitation, the innermost cushioning layer may be between 3 mm and 26 mm thick, although it may be thinner or thicker. By way of example, and not by way of limitation, the innermost cushioning pads may have a density of between 3.4 lbs/ft3 (approximately 0.016 g/cm3) and 25 lbs/ft3 (approximately 0.4 g/cm3), although they may be more dense or less dense.
In one embodiment, the innermost cushioning pad(s) 250 is covered by a fabric layer 260 (seen in
In one embodiment, and as suggested by
In one embodiment small holes are drilled in one or both of the cushioning shell and in the anti-ballistic hard shell for ventilation purposes and/or for attaching straps or other structures. The attachment holes may be covered by ballistic screws, nuts or bolts. Regardless, it will be appreciated that the size and number of holes in the anti-ballistic hard shell is kept to a minimum to limit the potential of penetration of projectiles through the holes. For purposes of the claims, a shell structure having holes for these purposes should still be considered a “continuous shell”.
The military helmet 210 has a concave outer surface and a convex inner surface. As seen in
The military helmets described are particularly suited for military use although they may be used for other purposes such as, by way of example only and not by way of limitation, a protective police helmet or an explosive ordinance disposal (EOD) helmet.
Turning now to
In one embodiment, the flexible thin cover 315 may be a fabric, film, foil, leather (actual or imitation) or other cover such as a ballistic nylon (a high denier nylon thread with a dense basket weave) that is used as a cover for the helmet. The flexible thin cover may provide a surface for printing graphics. The flexible thin cover may also protect the cushioning outer shell from damage. If desired, the flexible thin cover may extend around the periphery of the helmet to protect the periphery of the cushioning shell 320 and the cushioning spacer layer 330 and optionally the hard inner shell 340. Alternatively, if desired, a flexible band may be used to extend around the periphery and cover the peripheral edge of cushioning shell 320, the spacer layer 330 and optionally the hard shell 340. By way of example only, the thin cover may be between 0.1 mm and 10 mm thick, although it may be thinner or thicker. By way of another example, the flexible thin cover may be between 0.3 mm and 3.25 mm thick. By way of another example, the flexible thin cover may be between 1.0 mm and 1.5 mm thick. The thin cover 315 may be attached at one or more places to the cushioning shell 320, so that the cover may be removed from the shell 320 without damaging the shell. Alternatively, the thin cover may be glued, tacked or sewn to the shell 320. In one embodiment, the thin cover 315 covers the entire cushioning shell 320.
In one embodiment the cushioning shell 320 is comprised of foam. The foam may be an elastomeric, cellular (including microcellular) foam or any other desirable foam. In another embodiment, the cushioning shell is comprised of a soft resilient thermoplastic polyurethane (TPU). In another embodiment, the cushioning shell is comprised of open-cell polyurethane. In another embodiment, the cushioning shell is comprised of closed cell polyolefin foam. In another embodiment, the cushioning shell is comprised of polyethylene foam which may be a high or low density polyethylene foam. In all embodiments, the hardness of the cushioning shell is much lower than the hardness of the inner shell 340. For example, the hardness of the cushioning shell is typically described by the Shore A Durometer scale (typically Shore A 60 and under, and even more typically Shore A 30 and under), whereas the hardness of the inner shell is described by the Shore D Durometer scale.
In one embodiment, the outer surface of the cushioning shell 320 is generally (hemi-) spherical in shape. By way of example and not by way of limitation, the cushioning shell may be between 3 mm and 13 mm thick, although it may be thinner or thicker. By way of example, and not by way of limitation, the cushioning shell may have a density of between 3.4 lbs/ft3 (approximately 0.016 g/cm3) and 30 lbs/ft3 (approximately 0.48 g/cm3), although it may be more dense or less dense.
As shown in
As shown in
An alternative spacer layer 330d is seen in
In one embodiment, the hard inner shell 340 is comprised of a carbon fiber material. In one embodiment the inner shell material comprises a para-aramid synthetic fiber such as KEVLAR (a trademark of DuPont of Wilmington, Del.). In another embodiment the inner shell material comprises TWARON (a trademark of Teijin Twaron, B.V. of the Netherlands). In another embodiment, the inner shell material comprises ultra-high-molecular-weight polyethylene. In one embodiment the hard shell 340 is affixed to the spacer layer 330 (or 330d). Affixation can be done with glue, Velcro or any other affixation means. By way of example and not by way of limitation, the hard shell is between 2 mm and 20 mm thick, although it may be thinner or thicker. As another example, the hard inner shell 340 is between 7 mm and 12 mm thick.
Additional pads (not shown) may be provided inside the hard inner shell 340.
There have been described and illustrated herein several embodiments of a helmet. While particular embodiments have been described, it is not intended that the claims be limited thereto, as it is intended that the claims be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular materials for cushioning layers have been disclosed, it will be appreciated that other materials may be used as well. Similarly, while particular types of materials have been disclosed for the hard structural layer, it will be understood that other materials can be used. Also, while particular types of materials for the cover layers have been described, other materials can be used. In addition, while the shell was shown as being continuous, it will be appreciated that small holes may be drilled in the shell structure for ventilation purposes and for attaching straps or other structures. For purposes of the claims, such a shell should still be considered “continuous”. It will therefore be appreciated by those skilled in the art that yet other modifications could be made without deviating from the spirit and scope of the claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US2013/059626 | 9/13/2013 | WO | 00 |
Number | Date | Country | |
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Parent | 13617663 | Sep 2012 | US |
Child | 14427825 | US | |
Parent | 13670961 | Nov 2012 | US |
Child | 13617663 | US |