Patent Application
20180292181
It is well known that high-speed projectiles, such as those launched in response to an explosion, can cause significant injuries to people whom the projectiles encounter. For example, when a planted mine explodes due to a person walking over it, the person often receives significant injuries to his feet, legs, and torso as a result of shrapnel and other particles that are projected at high speed due to the explosion and which pass through the person's footwear and the bottom of the person's feet.
Typical materials for stopping high-speed projectiles, such as those used in armored vehicles or conventional bulletproof vests are not flexible and so are unsuitable for use in footwear to protect a person's feet, especially the bottoms thereof.
I have recognized that a material that is capable of stopping high-speed projectiles but yet is sufficiently flexible for use in various applications, such as to be used in footwear to protect a person's feet, especially the bottoms thereof, may be achieved, in accordance with the principles of the invention, by an enhanced ballistic material formed from interleaving layers of a ballistic material and layers of a gel matrix material that remains relatively soft and flexible. The ballistic material layer may be high tensile strength synthetic or polymeric fibers that are arranged in a mesh weave, each layer of which I call a “weave layer”. Each layer of the gel matrix material is what I call a “gel layer”. Preferably the gel matrix material is capable of investing the ballistic material, e.g., by having the gel matrix material fill the interstices of the fibers, which may be achieved through the use of heat and/or pressure. Furthermore, the combined material, i.e., the enhanced ballistic material, may be shaped, e.g., by molding.
Advantageously, the gel matrix material enhances the stopping power of the resulting multi-layer structure as compared to the same number of weave layers without gel matrix material and yet the resulting multi-layer structure is sufficiently flexible to be comfortable when inserted as in insert in a boot.
The weave layer may be made up of a) a woven para-aramid, such as Kevlar, a register trademark of DuPont, b) Twaron, a brand name of Teijin, c) an ultra high molecular weight polyethylene (UHMWPE), such as Spectra Shield, a registered trademark of Honeywell, or d) any mesh weave made to have similar properties. It may also be possible to employ as the weave layer ballistic plastics, or other ballistic materials that are not woven. All of the weave layers of a piece of enhanced ballistic material need not be made of the same material or be of the same thickness.
The weave layer may be made up of a) a woven para-aramid, such as KEVLAR®, hereinafter referred to as Kevlar, b) TWARON®, a woven para-aramid, c) an ultra high to molecular weight polyethylene (UHMWPE), such as SPECTRA SHIELD®, or d) any mesh weave made to have similar properties. It may also be possible to employ as the weave layer ballistic plastics, or other ballistic materials that are not woven. All of the weave layers of a piece of enhanced ballistic material need not be made of the same material or be of the same thickness.
The gel matrix material may be an elastomer, e.g., an elastic polymer or natural rubber, in that it should be a material that is compressible, flexible, and elastic. For ease of manufacturing, the gel matrix material may be a thermoplastic. Exemplary gel matrix materials include ethylene vinyl acetate, (CAS# 24937-78-8, also known as EVA), neoprene, silicone, rubber, nylon, latex, ELASTOSIL® R 750, a silicone rubber product of Wacker silicones (available at http://www.wacker.com/cms/en/global_contents/search/search.jsp), polyvinylchloride (PVC), polyether, or polyurethane. Those of ordinary skill in the art will be able to select an appropriate gel matrix material based on the compressibility, flexibility, and thermal properties of the application to which the enhanced ballistic material is to be put. All of the gel layers of a piece of enhanced ballistic material need not be made of the same material or be of the same thickness.
In some layers of conventional bullet proof vests, and the like, a projectile may pass through a layer by enlarging a gap between the fibers, either by tearing some fibers or stretching the fibers, to create, at least temporarily, a space for the projectile to pass through. By contrast, in one embodiment of the invention, where the weave layer is permeable to the gel material, e.g., due to there being some space between adjacent fibers of the weave layer, the weave layer is impregnated with the gel matrix material so as to reduce the ability of the fibers to quickly separate from each other, thus increasing resistance to the motion of the projectile. The impregnation may be achieved by heating and pressing the interleaved weave layers and gel layers together.
In one embodiment of the invention, the material is shaped into shoe insert, e.g., for insertion into a soldier's boots. Typically such insert is place between the bottom of the foot, or portion of the sock surrounding the bottom of the foot, and the inside bottom portion of the shoe. Indeed, such inserts may be provided integrally with each boot of a pair of boots, provided concurrently with the boots, or they may be a so-called “after-market” product or accessory that is available for purchase for insertion into completed boots that are purchased separately, e.g., as a retrofit to existing boots. Preferably, at least the bottom layer, with respect to a foot under which the material is located, is a weave layer. Also, preferably, the outer rim around the insert is sized so that to it comes up to partly envelop the soldier's foot when it is inserted into a boot containing the insert. To this end, it is advisable that the boot be sized so that it is somewhat, e.g., a half size, larger than the boot size that the soldier would otherwise wear. To protect a soldier's foot against the risk of fire in the event of an explosion underfoot, the gel matrix material employed in the various gel layers is preferably fireproof or at least the layer against the soldier's foot should preferably be a fire resistant weave layer, such as Kevlar.
For the wearer's comfort, it is possible to use in the layer that is up against the wearer's foot a material that provides odor and antibacterial protection such as MICROBAN® protection products which are available from Microban International Ltd., a global technology company headquartered in North America with an office located at 11400 Vanstory Drive, Huntersville, N.C. 28078, United States; Tel: +1 (704) 875-0806; and a website at www.microban.com.
As noted above, functionally, the impregnation of the individual fibers of the weave layers by the gel matrix material reduces the ability of a projectile to stretch and/or spread apart such individual fibers at and around the point of impact, thus making it more difficult for the projectile to part or break the fibers and so enhancing the resistance of each weave layer to the motion of the projectile. In other words, effectively the layers of gel matrix material reduce the range of motion of the weave layers because they are bound together as a whole combined unit. Furthermore, the various layers of gel matrix material cause the weave layers to at least partially work together in stopping the projectile. This may also contribute to better resistance to the spin of the projectile through the cooperation of all the joined layers.
Because the gel matrix material is elastic, the gel matrix material may also reflect the forward compressive shockwave back at the projectile, thus working to slow the projectile.
Additionally, the gel matrix material provides some spacing between adjacent weave layers. This spacing may be small. However, such spacing prevents the weave layers from pushing against each other as quickly as if there was no space between them at all, thus allowing each layer of weave material to operate at least somewhat independently in contributing to the slowing of the projectile, thereby sapping the kinetic energy of the projectile in a layer-by-layer fashion and thus improving stopping power. This is different than when there are simply multiple adjacent weave layers, because in that situation the projectile forces a more-in-front layer further back and adjacent to the next-further-back layer, thereby eliminating any space that there may originally have been between them, reducing the effective stopping power.
Furthermore, the gel matrix material reduces the deformation rate achievable by to each of the weave layers, thus allowing each of the weave layers to more strenuously resist the projectile and thereby slowing it more than each weave layer would achieve by itself. Additionally, the gel matrix material retards the ability of each subsequent weave layer to be dragged through the hole path created by the impact from layer to layer of the projectile, as compared to independent layers of weave material, which often happens for some layers typically after the first few in multi-layer stopping arrangements.
Advantageously, the inventive material further contributes to shielding the wearer's foot from heat that can cause bodily injury, such as burns, melting of flesh, and fusing of flesh to clothing and footwear. Such heat is typically generated in proximity to an explosion, which may launch high-speed projectiles, or may be the result of fires.
The enhanced ballistic material could also be used for vehicle floor mats, e.g., for school buses, armored vehicles, cars, trucks, Humvees, boats, trains, plains, and the like, to protect such vehicles from explosions, e.g., mines or improvised explosive devices (IEDs). The enhanced ballistic material also may be used to line the interior of such vehicles. Doing so would protect against penetration by depleted projectiles or chunks of shrapnel from the projectile or armor which might otherwise fly around the crew compartment. When so used the enhanced ballistic material would provide some cushioning as compared to hard steel interior surfaces that would otherwise be exposed. This could be especially useful when the vehicle travels over uneven surfaces, thereby creating a bumpy ride which tends to cause the crew to collide with the walls and ceiling.
Other applications may include use of the enhanced ballistic material as a) the inner liner of a helmet; b) a liner for a vest; c) part of the protective suit worn by tank personnel, e.g., as a replacement for one or more layers thereof; d) an elbow or knee pad, e) an ankle protector, f) an arm pit protector, h) a face mask, i) a space suit liner; j) a space craft wall, e.g., to provide interior or exterior, protection; k) a seat cushion, l) a hull, or liner thereof, of a watercraft, m) a fuselage, or liner thereof, of an aircraft, or n) part of a wetsuit or dry suit, o) the like where protection is required but some degree of softness and/or flexibility would be desirable. Note that an advantage of using the enhanced ballistic material in space applications is that the matrix material can be made airtight and one or more of the inner layers can remain airtight even after the stopping of small bits of space debris by the outer layers.
Tests have shown that while it takes 12 layers of conventional Kevlar to stop a 22 caliber long rifle hypervelocity bullet, such a bullet can be stopped by 4 to 6 layers of enhanced ballistic material, e.g., 6 layers of Kevlar and 5 layers of silicon. Thus, advantageously, not only is the enhanced ballistic a) material more comfortable due to its flexibility and b) better suited to be in close contact with the body, but it is also to significantly stronger than conventional Kevlar and similar protections. Further advantageously, use of the gel matrix material should reduce the overall cost for the same level of provided protection.
In the drawing:
The following merely illustrates the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples and conditional language recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.
In the claims hereof any element expressed as a means for performing a specified function is intended to encompass any way of performing that function. The invention as defined by such claims resides in the fact that the functionalities provided by the various recited means are combined and brought together in the manner which the claims call for. Applicant thus regards any means which can provide those functionalities as equivalent as those shown herein.
Unless otherwise explicitly specified herein, the drawings are not drawn to scale.
In the description, identically numbered components within different ones of the FIGS. refer to the same components.
Ballistic material layers 103 may each be made of high tensile strength synthetic or polymeric fibers that are arranged in a mesh weave. Each layer of ballistic material layers 103 is what I call a “weave layer”. Each layer of gel matrix material 105 is what I call a “gel layer”. The ballistic material of each weave layer may be a) a woven para-aramid, such as KEVLAR®, hereinafter referred to as Kevlar, b) TWARON®, a woven para-aramid, c) an ultra high molecular weight polyethylene (UHMWPE), such as SPECTRA SHIELD®, or d) any mesh weave made to have similar properties. It may also be possible to employ as the ballistic material of the weave layer ballistic plastics, or other ballistic materials, that are not woven. All of the weave layers of a piece of enhanced ballistic material need not be made of the same material or be of the same thickness.
Gel matrix material 105 may be an elastomer, e.g., an elastic polymer or natural rubber, in that it should be a material that is compressible, flexible, and elastic. Preferably the gel matrix material is capable of investing the ballistic material, e.g., through the use of heat and/or pressure. Furthermore, the combined material, i.e., enhanced ballistic material 101, may be shaped, e.g., by molding. For ease of manufacturing, the gel matrix material may be a thermoplastic. Exemplary gel matrix materials include ethylene vinyl acetate, (CAS# 24937-78-8, also known as EVA), neoprene, silicone, rubber, nylon, latex, ELASTOSIL® R 750, a silicone rubber product of Wacker silicones (available at http://www.wacker.com/cms/en/global_contents/search/search.jsp), polyvinylchloride (PVC), polyether, or polyurethane. Those of ordinary skill in the art will be able to select a particular gel matrix material based on the compressibility, flexibility, and thermal properties of the application to which the enhanced ballistic material is to be put. All of the gel layers of a piece of enhanced ballistic material need not be made of the same material or be of the same thickness.
In some layers of conventional bullet proof vests, and the like, a projectile may pass through a layer by enlarging a gap between the fibers, either by tearing some fibers or stretching the fibers, to create, at least temporarily, a space for the projectile to pass through. By contrast, in one embodiment of the invention, where the weave layer is permeable to the gel material, e.g., due to there being some space between adjacent fibers of the weave layer, the weave layer is impregnated with the gel matrix material in a manner that reduces the ability of the fibers to quickly separate from each other, thus increasing resistance to the motion of the projectile. The impregnation may be achieved by heating and pressing the interleaved weave layers and gel layers together.
Advantageously, the gel layer enhances the stopping power of the resulting multi-layer structure as compared to the same number of weave layers without gel material, e.g., by having the gel matrix material fill the interstices of the fibers, while leaving it sufficiently flexible to be comfortable when inserted as in insert in a boot.
Functionally, the gel matrix material reduces the ability of a projectile to stretch and/or spread apart, e.g., when impregnated, the individual fibers of the weave layers at and around the point of impact, thus making it more difficult for the projectile to part or break the fibers, thereby enhancing the resistance of each weave layer to the motion of the projectile. Effectively the layers of gel matrix material reduce the range of motion of the constituent portions, e.g., fibers, as well as of the individual weave layers, which are bound together to form a whole combined unit. Furthermore, the layers of gel matrix material cause the weave layers to at least partially work together in stopping the projectile. This may also contribute to better resistance to the spin of the projectile through the cooperation of all the joined layers.
Because the gel matrix material is elastic, the gel matrix material may also reflect the forward compressive shockwave back at the projectile, thus working to slow the projectile.
Additionally, the gel matrix material provides some spacing between adjacent weave layers. This spacing may be small. However, such spacing prevents the weave layers from pushing against each other as quickly as if there was no space at all, thus allowing each layer of weave material to operate at least somewhat independently in contributing to the slowing of the projectile, thereby sapping the kinetic energy of the projectile in a layer-by-layer fashion and thus improving stopping power. This is different than when there are simply multiple independent adjacent weave layers, because in that situation the projectile forces a more-in-front layer further back and adjacent to the next-further-back layer, thereby eliminating any space that there may originally have to been between them, reducing the effective stopping power. Furthermore, the gel matrix material reduces the deformation rate achievable by each layer, thus allowing each layer to more strenuously resist the projectile and thereby slowing it more than each weave layer would achieve by itself. Additionally, the gel matrix material retards the ability of each subsequent weave layer to be dragged through the hole path created by the impact from layer to layer of the projectile, as compared to independent layers of weave material, which often happens for some layers typically after the first few in multi-layer stopping arrangements.
Thus, advantageously, the gel matrix material enhances the stopping power of the resulting multi-layer structure as compared to the same number of weave layers without gel matrix material and yet the resulting multi-layer structure is sufficiently flexible to be comfortable when inserted as in insert in a boot. For example, tests have shown that while it takes 12 layers of conventional Kevlar to stop a 22 caliber long rifle hypervelocity bullet, such a bullet can be stopped by 4 to 6 layers of enhanced ballistic material, e.g., 6 layers of Kevlar and 5 layers of silicon. Thus, advantageously, not only a) is the enhanced ballistic material more comfortable due to its flexibility, and b) better suited to be in close contact with the body, but c) it is also significantly stronger than conventional Kevlar and similar protections. Further advantageously, use of the gel matrix material should reduce the overall cost for the same level of provided protection.
It is recommended that insert 201 have rim 203 that is sized so that it comes up slightly to partly envelop the soldier's foot when it is inserted into a boot containing the insert so as to provide additional protection for the soldier's foot. To this end, it is further recommended that a soldier wear a boot that is somewhat larger, e.g., one-half size larger, than he would otherwise wear, to allow sufficient room to fit insert 201 into the boot.
To protect a soldier's foot against the risk of fire in the event of an explosion underfoot, the gel matrix material is preferably fireproof or the layer that is ultimately adjacent to the soldier's foot or sock should preferably be a fire resistant weave layer, such as Kevlar. Advantageously, the inventive material further contributes to shielding the wearer's foot from heat that can cause bodily injury, such as burns, melting of flesh, and fusing of flesh to clothing and footwear. Such heat is typically generated in proximity to an explosion, which may launch high-speed projectiles, or may be the result of a fire.
For the wearer's comfort, it is possible to use in the layer that is against the wearer's foot a material that provides odor and antibacterial protection such as MICROBAN® protection products, which are available from Microban International Ltd., a global technology company headquartered in North America with an office located at 11400 Vanstory Drive, Huntersville, N.C. 28078, United States; Tel: +1 (704) 875-0806; and a website at www.microban.com.
Note that the properties of the layer closest to the wearer's foot would be selected by designer based on the particular threats expected to be encountered and protected against in the event that a suitable material for countering all the conditions cannot be selected. For example, in some applications where fire is expected, e.g., where there is a high risk of explosion, a fire resistant material may be selected, whereas when the risk of explosion is minimal but there is likely to be sweat odor an antibacterial protection may be selected in the event both protections cannot be adequately provided simultaneously.
For example, interleaved layers of ballistic material 103 and the layers of gel matrix material 105 are first placed in a mold, which is then pressed together and heated to form the desired shape. To this end, layers of gel material may be sprayed, brushed or applied to each lower layer of ballistic material to insure that the ballistic material is appropriately covered by the gel material. Of course, one of ordinary skill in the art will readily recognize that the final thickness of the gel matrix material layers may, at least in part, depend on the amount of pressure and the heat applied.
Returning to
The enhanced flexible ballistic material could also be used for vehicle floor mats, e.g., for school buses, armored vehicles, cars, trucks, Humvees, boats, trains, plains, and the like, to protect such vehicles from explosions, e.g., mines or improvised explosive devices (IEDs). Other applications may include use of the enhanced ballistic material as a) the inner liner of a helmet; b) a liner for a vest; c) part of the protective suit worn by tank personnel, e.g., as a replacement for one or more layers thereof; d) an elbow or knee pad, e) an ankle protector, f) an arm pit protector, h) a face mask, i) a space suit liner; j) a space craft wall, e.g., to provide interior or exterior, protection; k) a seat cushion, l) a hull, or liner thereof, of a watercraft, m) a fuselage, or liner thereof, of an aircraft, or n) part of a wetsuit or dry suit, o) the like where protection is required but some degree of softness and/or flexibility would be desirable. Note that an advantage of using the enhanced ballistic material in space applications is that the matrix material can be made airtight and one or more of the inner layers can remain airtight even after the stopping of small bits of space debris by the outer layers.
As noted hereinabove, the amount of gel matrix material in between each layer of ballistic material depends on the application of the enhanced ballistic material. In particular, tradeoffs between softness, stopping power, thickness, weight, durability, and material cost are required. Thus, for example, a boot liner needs to provide flexibility, durability in maintaining its shape as it is constantly walked upon, relatively light weight, moderate softness, compactness, and good stopping power. A bus floor liner need not be especially soft, e.g., less soft than the boot application, it may be heavy and need not be compact so it may have many layers, it should be as durable as the floors of buses typically are, is barely flexible, in that it is meant as a soft liner for a hardened compartment, and has the most stopping power. A helmet liner, which is intended to prevent a catastrophic failure of the helmet from killing the wearer, should be lightweight and soft but need not be compact or durable.
A unique approach to helmet design and space craft walls is to take individual layers of enhanced ballistic material and interleave between them layers of foam to increase the softness and reduce the weight. Preferably the foam is made from the same material that is employed for the gel material of the enhanced ballistic material to provide improved chemical matching and bonding. to Preferably, the ballistic material layer should be evenly spaced over the entirety of the thickness of the enhanced ballistic material.
This application is a continuation of U.S. patent application Ser. No. 13/867,677 filed on Apr. 22, 2013 which claimed the benefit of U.S. provisional application Serial No. 61636665 (61/636,665) filed on Apr. 22, 2012, the contents of both of which are herein incorporated by reference as though fully set forth herein.
| Number | Date | Country | |
|---|---|---|---|
| 61636665 | Apr 2012 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13867677 | Apr 2013 | US |
| Child | 16011586 | US |
