Lightweight Integration Of Shock Absorbing Technology In A Protective Device

TECHNICAL FIELD

The present invention relates to protective devices, such as, for example, helmets, that utilize one or more efficient, fluid-containing shock absorbers in place of a protective device's existing shock absorbing material to minimize the overall weight of the protective device and provide additional ventilation for the same. The more efficient, fluid-containing shock absorbers yield improved impact force attenuation but occupy substantially less volume in the protective device than heretofore known shock absorbing material.

BACKGROUND

Protective equipment devices, particularly helmets, are commonly used in a variety of industries and activities, including sports, military, construction, law enforcement, vehicle applications, and more. Many protective gears and helmets seek to protect wearers by minimizing the force imposed on the wearer's body, head, and/or brain by impacts from external sources. However, this equipment must generally be developed within certain confines related to size, weight, field of view, etc. such that the wearer experiences a level of comfort that is acceptable and the wearer is not substantially restricted by the equipment in their activity. Therefore, the amount of material used to create these wearable protective devices is finite and restricted based on the type of activity the device will be used in. In some cases, the weight, size, or field of view allowed when wearing the equipment may be restricted by governing bodies that oversee standardized testing protocols and manufacturing requirements for protective equipment.

Recently, a number of technologies have been developed which seek to improve the efficiency of shock absorbers in helmets and other applications within a given amount of space. While these advances have generally improved the state-of-the-art in helmet technology, an issue still remains that these technologies can be relatively heavy when compared to older, less space-efficient technologies.

An optimal solution for decreasing helmet weight while maintaining efficient attenuation of impacts would be to use the minimum amount of shock absorbers needed to reach the target attenuation of a given impact, rather than filling the full volume of the helmet with shock absorbing material. The positioning of the shock absorbers and the means of making the devices fit comfortably within protective devices while also providing ample protection would require careful thought, such that certain areas of the head are not left unprotected or certain areas do not present the wearer's head with focalized pressure points.

A need, therefore, exists for improved protective devices. Specifically, a need exists for improved protective devices that utilize shock absorbers that minimize weight within the protective devices. In addition, a need exists for improved protective devices that utilize the minimum amount of shock absorbers and other structural material.

Moreover, a need exists for improved protective devices that provide positioning of the shock absorbers to provide necessary protection but also provide comfort to a user when wearing and/or using the protective devices. Specifically, a need exists for improved protective devices that provides protection so that a user's body parts, namely their heads, are not left unprotected. Moreover, a need exists for improved protective devices that do not present a wearer's body part with focalized pressure points that may be uncomfortable or cause damage or injury to the user.

SUMMARY OF THE INVENTION

It is, therefore, an advantage and objective of the present invention to provide improved protective devices.

Specifically, it is an advantage and objective of the present invention to provide improved protective devices that utilize shock absorbers that minimize weight within the protective devices.

In addition, it is an advantage and objective of the present invention to provide improved protective devices that utilize the minimum amount of shock absorbers and other structural material.

Moreover, it is an advantage and objective of the present invention to provide improved protective devices that provide positioning of the shock absorbers to provide necessary protection but also provide comfort to a user when wearing and/or using the protective devices, such as via improved ventilation of the same.

Specifically, it is an advantage and objective of the present invention to provide improved protective devices that provides protection so that a user's body parts, namely their heads, are not left unprotected.

Moreover, it is an advantage and objective of the present invention to provide improved protective devices that do not present a wearer's body part with focalized pressure points that may be uncomfortable or cause damage or injury to the user.

Stated another way, a protective device for a user to wear comprises a carrier spaced apart from a shell. The carrier includes a pocket. A first shock absorber includes a bladder and a reservoir, each containing a liquid. The bladder and the reservoir are fluidly interconnected. One of the bladder and the reservoir is positioned between the shell and the carrier. The other one of the bladder and the reservoir is positioned within the pocket. In response to an external load, the shell is movable relative to the carrier and the liquid flows between the bladder and the reservoir.

Additional features and advantages of the present invention are described in, and will be apparent from, the detailed description of the presently preferred embodiments and from the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing figures depict one or more implementations in accord with the present concepts, by way of example only, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements.

FIG. 1 illustrates a helmet covering a majority of the wearer's head, featuring shock absorbers arranged in a manner such that they are grouped together in similar groups of three, in an embodiment of the present invention;

FIG. 2 illustrates a helmet covering a significant portion of the wearer's head above the ear, featuring shock absorbers arranged in a manner such that they are grouped together in groups of varying number, but more than one, in an embodiment of the present invention;

FIG. 3 illustrates groups of shock absorbers that are disposed between the outer shell of a helmet and an inner surface that contacts the wearer's head, in an embodiment of the present invention;

FIG. 4 illustrates groups of shock absorbers that are disposed between the outer shell of a helmet and an inner surface that contacts the wearer's head, in an embodiment of the present invention;

FIGS. 5A-5C illustrate an inside view of a helmet constructed from an exterior shell and an interior rigid foam directly connected to the shell having a single shock absorber disposed therein, in an embodiment of the present invention;

FIG. 6 illustrates peak force data from impact experiments in which helmets are worn by a test head-form and dropped onto a force plate, in an embodiment of the present invention;

FIG. 7 illustrates a cross sectional view of a helmet demonstrating an advantage in improved ventilation by utilizing the lightweight integration of shock absorbers in a helmet, in an embodiment of the present invention;

FIG. 8 illustrates a cross sectional view of a helmet demonstrating a connection between inner surfaces, in an embodiment of the present invention;

FIG. 9 illustrates a cross sectional view of a helmet in which shock absorbers are embedded within a top and bottom layer of foam, in an embodiment of the present invention;

FIGS. 10A-10C illustrate close up views of shock absorbers placed between two surfaces for use in a helmet or other protective device, in an embodiment of the present invention;

FIG. 11 illustrates a helmet that is comprised of a layer of foam attached to an outer shell, in an embodiment of the present invention;

FIG. 12 illustrates an exemplary shock absorber, including a centralized bladder circumscribed by a reservoir;

FIG. 13 depicts another alternate embodiment shock absorber, including a plurality of spaced apart bladders fluidly interconnected to a common reservoir;

FIG. 14 is an exploded perspective view of an exemplary helmet equipped with a carrier including pockets in receipt of spaced apart shock absorbers;

FIG. 15 is a fragmentary cross-sectional view of an alternate embodiment helmet;

FIG. 16 is a fragmentary cross-sectional view of another alternate embodiment helmet;

FIG. 17 is a fragmentary cross-sectional view of another alternate embodiment, helmet;

FIG. 18 is a partial top view of another alternate embodiment helmet having an outer shell removed;

FIG. 19 is a cross-sectional top view of another alternate embodiment helmet; and

FIG. 20 is a cross-sectional top view of the helmet depicted in 19 having the outer shell rotated relative to the inner shell.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 1 illustrates a protective device, namely a helmet 10 that may cover a portion or a majority of the wearer's head 12, featuring shock absorbers 14 arranged in a manner such that they may be grouped together in similar groups 16 of three. Each group 16 of three shock absorbers 14 may be disposed between an outer shell 18 of the helmet 10 and an inner surface 20, wherein the inner surfaces 20 may preferably contact the user's head 12. There may be, preferably, a single outer shell, while there are preferably a plurality of inner surfaces. The groups 16 of shock absorbers 14 may be spread out such that no inner surface 20 may touch another inner surface 20 while at rest, and no shock absorber 15 may touch another shock absorber 14.

FIG. 2 illustrates a protective device, namely a helmet 50 covering a significant portion of a wearer's head 52 above his or her ears, featuring a plurality of shock absorbers 54 arranged in a manner such that they may be grouped together in groups 56 of varying number, such as two, three, four, or more, but more than one. Each group 56 of shock absorbers 54 may be disposed between an outer shell 58 of the helmet 50 and an inner surface 60 of varying shapes and sizes, wherein the inner surfaces 60 may preferably contact the user's head 52. There may be a single outer shell 58, while there are a plurality of inner surfaces 60. The groups 56 of shock absorbers 54 may be spread out such that no inner surface 60 touches another inner surface 60 at rest, and no shock absorber 54 touches another shock absorber 54. In some cases, the shock absorbers may be connected to one another, such as illustrated in FIG. 2 via an inter-surface connection 62, while in other cases they may stand alone without connection between surfaces 60. The inter-surface connection 62 may be an elastic or tensile component that may be used to connect inner surfaces to one another, such that when the inner surfaces translate away from each other, the elastic or tensile component will tighten and/or return the inner surfaces to their original positions.

FIG. 3 illustrates a helmet 100 that may be worn or disposed on a user's head 102 comprising a group 106 of shock absorbers 104 that may be disposed between an outer shell 108 of the helmet 100 and an inner surface 110 that contacts the wearer's head 102. Both the outer shell 108 and the inner surface 110 may be made of a continuous material, where there is a single outer shell 108 and a single inner surface 110, with the plurality of shock absorbers 104 disposed therebetween. The inner surface may be made from a thicker material, such as a thick foam, or other like material providing additional shock absorbing properties. Optionally, each of the shock absorbers may be connected to each other via a material 112. The material may also form passages or tunnels connecting one shock absorber to at least one other shock absorber, allowing fluid to flow through from one shock absorber to another shock absorber, especially when compressed due to an impact.

FIG. 4 illustrates a helmet 150 for a user's head 152 comprising groups 156 of shock absorbers 154 that may be disposed between an outer shell 158 of the helmet 150 and an inner surface 160 that may contact the wearer's head 152. Both the outer shell 158 and the inner surface 160 may be made of a continuous material, where there is only one single outer shell 158 and one inner surface 160. The inner surface 160 and outer shell 158 may be made of the same or a similar material, or the inner surface may be made of a different material. The inner surface 160 may contact a second group 156 of shock absorbers 154 (or, in an alternate embodiment, a separate shock absorbing material, such as a foam or the like) which may directly contact the wearer's head 152.

FIGS. 5A-5C illustrate an inside view of a helmet 200 constructed from an exterior shell 202 and an interior rigid foam 204 that may be directly connected to the shell 202. A section (not shown) of the interior rigid foam 204 may be removable to make space for a single shock absorber 208 placed centrally in an empty space 210 formed from the removed section of the interior rigid foam 204. The single shock absorber 208 may be placed so as to directly contact an interior surface 212 of the outer shell 202, as illustrated in FIG. 5A. A plate 214 of a material, such as a rigid foam, for example, may be placed over the shock absorber 208, as illustrated in FIGS. 5B and 5C. Together, the plate 214 of rigid foam and the inner surface of the remainder of the interior rigid foam 204 may thus form an inner surface 216 that may directly contact a wearer's head (not shown). FIG. 5C illustrates a cross-sectional view of the helmet 200 showing the exterior shell 202, the interior rigid foam 204, the plate 214 of rigid foam material, and the single shock absorber 208 placed centrally in the empty space 210.

FIG. 6 illustrates peak force data from impact experiments in which helmets are worn by a test head-form and dropped onto a force plate. An unmodified, standard equestrian helmet made from continuous expanded polystyrene foam was compared to a lightweight liquid shock absorber helmet made by cutting out a large section of the foam and replacing it with a small liquid shock absorber (as described above with reference to FIGS. 5A-5C). Both helmets are nearly identical in mass. The “lightweight liquid helmet” (i.e., the helmet having the shock absorber therein) may make better use of its mass by lowering the peak force (in kN) of the impact relative to the standard, unmodified helmet. Two impact velocities were tested, one at 3.0 m/s and the other at 4.9 m/s.

FIG. 7 illustrates a cross-sectional view of a helmet 250 demonstrating an advantage in improved ventilation by utilizing the lightweight integration of shock absorbers 252 in the helmet 250. Specifically, the use of a limited number of shock absorbers 252 may allow for more open space in the helmet, which may in turn allow for improved ventilation both through the helmet 250 and within the helmet 250 (i.e., between an outer shell 254 and a plurality of inner surfaces 256 that may contact the wearer's head). The inner surfaces 256 may be attached to the outer shell 254 or outer surface of the helmet by means of elastic or tensile components that may allow for compression of the inner surfaces 256 towards the outer shell 254 but may restrict movement of the inner surfaces 256 and shock absorbers 252 within a desired range.

FIG. 8 illustrates a cross-sectional view of a helmet 300 demonstrating a plurality of shock absorbers 302, each having an inner surface 304, where there may be a connection 306 between respective inner surfaces 304. The shock absorbers 302 may be disposed between a plurality of inner surfaces 304, respectively and an outer shell 308 of the helmet 300. The inner surfaces 304 may be attached to one another with, for example, relatively thin elastic or tensile components that may restrict the movement of the inner surfaces 304 relative to one another. Alternatively, the inner surfaces 304 may be connected to one another with one or more rigid connections 306 that may be designed to break at a predetermined force.

FIG. 9 illustrates a cross sectional view of a helmet 350 in which a plurality of shock absorbers 352 are embedded within a top and bottom layer of foam 354, 356, respectively. These layers of foam 354, 356 may serve to hold the shock absorbers 352 in a desired location within the helmet 350, may provide additional impact protection, and/or may further provide the user with more optimal helmet 300 comfort and fit on his or her head 358.

FIGS. 10A-10C illustrate close up views of shock absorbers 400 placed between two surfaces, an outer surface 402 and an inner surface 404, for use in a helmet or other protective device (not shown). The shock absorbers 400 may make contact with a relatively low amount of surface area of the surfaces 402, 404. FIG. 10A illustrates an embodiment wherein both surfaces 402, 404 that may contact the shock absorber 400 are flat. The shock absorber 400 may be adhered to one or more of the surfaces 402, 404 with a glue, adhesive, hook and loop fastener, double-sided tape, a stitch, a rigid fastener, or other like fastener. FIG. 10B illustrates an embodiment wherein the outer surface 402 may be flat (i.e., without pockets, holes, or apertures in which the shock absorber 400 may be contained), while the inner surface 404 may have pockets 406 which may house or otherwise the shock absorber 400 and give it space to deform or move while keeping it within a relatively defined space within the pocket 406. In addition, when recording an impact, one or more openings within the shock absorbers 400 may allow fluid to spill therefrom, contributing to the deformation and energy absorption of the shock absorbers 400. In an alternate embodiment, fluid may collect within the pockets 406, providing the fluid with a place to be spilled thereto. FIG. 10C illustrates an embodiment wherein a surrounding foam 408 of low density may be disposed between the outer surface 402 and the inner surface 404, which may hold the shock absorbers' 400 positions and orientations relatively constant thereby stabilizing the inner and outer surfaces, 402, 404, respectively, relative to one another.

FIG. 11 illustrates a helmet 450 that may comprise a layer 452 of foam that may be attached to an outer shell 454. The layer 452 of foam may have one or more pockets or cutouts 456 in it that may house shock absorbers 458 therein. Each of the shock absorbers 458 may have a casing or outer covering 460 that may have threaded or have ridges 462 that may be utilized to engage mating threads or ridges 464 within the layer 452 of foam, specifically at the cutouts 456 thereof, thereby allowing or aiding the shock absorbers 458 to remain in place when inserted into the cutouts 456 within the layer 452 of foam that may be affixed to the outer shell 454 of the helmet 450.

FIG. 11 further illustrates that the shock absorbers 458 may be provided without an inner layer that may be disposed between the shock absorbers and a user's head (not shown). Specifically, in an alternate embodiment of the present invention, shock absorbers of the present invention may be disposed within a protective device, as described herein, and may directly contact a user's body part, such as the user's head in a helmet, without an inner layer disposed between the shock absorbers and the user's head.

A protective device, such as a helmet, for example as described herein, typically contains an outer shell and one or more layers of shock absorbing materials used to attenuate the severity of impacts to the wearer. Shock absorbers filled entirely or partially with a fluid (e.g., a liquid, a gas, or a gel-like substance) have been found to yield highly efficient attenuation to impacts and represent the state-of-the-art in shock absorbing technologies. However, these newer shock absorbers containing fluids are often heavy relative to their predecessors. Helmets, for example, sometimes have regulations that restrict their maximum weight and users may prefer to wear a lighter helmet. If implemented into a helmet in such a manner that they directly replace their predecessor shock absorbers, these new fluid-containing shock absorbers will likely increase the overall weight of the helmet.

Therefore, in order to reduce the weight of a helmet while utilizing these newer, heavier technologies, the present invention uses fewer shock absorbers total in the helmet. Utilizing a more efficient, fluid-containing shock absorber in place of a helmet's existing shock absorbing material may yield improved impact force attenuation even in cases where the shock absorber occupies substantially less volume in the helmet than the original shock absorbing material in an effort to match the helmet's original weight, as illustrated in FIG. 6, for example.

When using fewer shock absorbers, their placement and arrangement becomes especially critical. This is because each shock absorber is now responsible for protecting a greater surface area on the head. The shock absorbers may also preferably be arranged and oriented such that they provide a sufficient fit and comfort for the wearer. This may be difficult for a small group of small shock absorbers, therefore if the shock absorbers are disposed between the outer shell and another surface closer to the wearer's head, the pressure from this shock absorber can be distributed across a larger area, thus providing improved fit, comfort, and protection. Embodiments of such a helmet could include a single shock absorber disposed between the outer shell of the helmet and an inner surface within the helmet (as illustrated in FIGS. 5A, 5B, 5C) or a plurality of shock absorbers between the outer shell and one or more inner surfaces of the helmet (as illustrated in FIGS. 1, 2, 3, and 4).

Moreover, the shock absorbers of the present invention, as described herein, preferably having a fluid disposed therein may have pathways or gaps to allow fluid to flow from within the shock absorbers to outside the shock absorbers, thereby allowing further compression of the shock absorbers and absorption of energy thereby. Thus, the pathways or gaps may lead to open spaces contained between the inner and outer layers, or within one or both of the inner or outer layers, or between adjacent shock absorbers. Preferably, the pathways or gaps may allow fluid that flows therethrough to flow back into the shock absorbers, thereby resetting the same after an impact. Alternatively, the shock absorbers may be utilized once such that when fluid flows therefrom through the pathways and/or gaps, the fluid may remain external to the shock absorbers, requiring replacement thereof.

In a preferred embodiment, the inner and outer surfaces are substantially larger than the faces of the shock absorbers they make contact with (as illustrated in FIG. 10A). In another embodiment, there may be a continuous material that contains the shock absorbers within it that is disposed between the surfaces. In another embodiment, the inner surface may be made from a material that is equal in thickness or substantially thicker than the outer surface and may have holes, pockets, or depressions in it that house the shock absorbers (as illustrated in FIG. 10B). The section of material at the bottom of the holes or depressions may be designed such that it breaks at a predetermined force. This breakage may function as a signal to the wearer that it is time to replace their helmet or other protective device. In some embodiments, the inner surface may directly contact the wearer's head (as illustrated in FIGS. 1, 2, and 3) and in other cases the inner surface may contact another group of shock absorbers or another material (as illustrated in FIG. 4). The inner surface can range in thickness and material composition and may be made from a material that itself has shock absorbing capabilities. The inner surface may be a single, continuous surface that mimics the shape of the outer shell or wearer's head (as shown in FIGS. 3 and 4), or the inner surface may consist of a plurality of surfaces that together fit to the head (as shown in FIGS. 1 and 2). The shock absorbers disposed between these two surfaces may be connected to one another (as shown in FIG. 3) or stand independently (as shown in FIG. 1).

The shock absorbers disposed between the two surfaces should be able to compress sufficiently, such that when compressed, the two surfaces will move closer to one another. The shock absorbers should also shear, such that when shearing the two surfaces move opposite laterally to one another. If the shock absorbers twist, the two surfaces should rotate opposite one another as well.

The inner surface and outer surface on either side of the shock absorber(s) may be connected to one another in a variety of ways. In one embodiment, they may be connected to each other solely by their attachments to the shock absorber(s) between them (as illustrated in FIG. 1). In another embodiment, springs may attach the outer and inner surfaces. In another embodiment, they may be additionally connected with strings, cables, rubber bands, or other tensile or elastic elements (as shown in FIG. 7). These strings, cables, rubber bands, or other tensile or elastic elements may additionally serve to pre-pressurize the fluid-filled shock absorbers to a desired internal pressure. In another embodiment, they may be connected rigidly, either around the perimeter or nearer to the center of the surface(s). In another embodiment, a portion of the inner surface may be connected rigidly to the outer surface, such as with an adhesive, Velcro, a double-sided tape, a stitch, or a fastener, while a portion may be connected with strings, cables, rubber bands, or other tensile or elastic elements. In another embodiment, a low-density foam may exist between the two surfaces and surround the shock absorber(s), thus stabilizing the positioning of the two surfaces and the positioning and orientation of the shock absorber(s) (as shown in FIG. 10C). In some embodiments, the shock absorbers may be connected to only one of the inner or outer surfaces, and not both, but may make contact with both surfaces upon compression during an impact.

The location of the inner and outer surfaces within the protective device may vary amongst embodiments. In one embodiment, the outer surface may be the surface farthest from the wearer, such as the outer shell. In another embodiment, the outer surface may not be the farthest surface from the wearer but may make contact with the surface farthest from the wearer. Similar to the outer surface, in one embodiment, the inner surface may be the surface nearest to the wearer such that it makes contact with the wearer. In another embodiment, the inner surface may not be the surface closest to the wearer but may make contact with the surface nearest the wearer, such as a secondary layer of shock absorbing material (as illustrated in FIG. 4) or a layer of comfort padding.

In embodiments where a plurality of inner surfaces exist, the inner surfaces may be connected to one another or stand independent of each other. The inner surfaces may be connected to each other by strings, cables, rubber bands, or other tensile or elastic elements or rigidly by plastics, stiff foams, or metal pieces. In one embodiment, the inner surfaces may be connected by a material intended to break at a predetermined force. For example, the inner surfaces could be made of an expanded polystyrene foam and connected to one another by thin pieces of expanded polystyrene foam intended to break upon high energy impact. This breakage of the material may function as a visible signal to the user that it is time to replace their helmet or other protective device. The plurality of surfaces and connections could be manufactured using a mold or similar piece of tooling as one uniform piece or varying thickness and geometry.

In one embodiment, one or both of the inner and outer surfaces may be made of a substantially low-density foam, such that the foam surrounds the shock absorbers and holds them in place, but easily compresses when force is applied (as illustrated in FIG. 9). In this embodiment, the foam may compress a desired amount to provide optimal fit and comfort to the wearer. When impacted, this foam will quickly compress until reaching the shock absorber, thus engaging it.

It may be necessary for shock absorbers to be various shapes and sizes depending on the application and shape and size of the wearer's head. In some cases, their aspect ratio may be greater than one, such that they are wider than they are tall (as shown in FIGS. 2, 3, and 4). In other cases, their aspect ratio may be less than one, such that they are taller than they are wide (as illustrated in FIGS. 1 and 8). In other cases, the aspect ratio may be exactly one, such that the shock absorbers' height and width are equal. The aspect ratio may depend on the application and type of impacts expected and can vary among different shock absorbers in the same helmet.

A helmet may also consist of a layer of foam directly connected to the outer shell of the helmet and have slots cut out in it, such that a shock absorber can be inserted into the slots (as illustrated in FIG. 11). The shock absorber may be encased in a material, such as a foam, that has threads or ridges on the outside of it, such that it may be securely positioned inside the layer of foam during use of the helmet but can be replaced by the wearer or an individual trained in servicing the helmet.

Other means of making the total weight of the protective device lighter may include reducing the density of the shock absorbers while keeping their external dimensions the same. One method of doing this includes mixing the contained fluid with microspheres or another density-reducing agent. Another method of doing this is to make the shock absorber hollow at the center, such that it is shaped like a toroid or other hollow geometry that contains the fluid.

In addition to low equipment weight, users of protective equipment often desire a high amount of ventilation, as the settings in which they use the protective gear usually involve strenuous activity (such as sports or military combat). Monolithic foams often fill nearly the entire volume of a helmet and, therefore, do not allow much air flow. By using a small amount of discrete shock absorbing units, this may allow for the addition of more and/or larger ventilation holes in the shell of a helmet, such that air can travel through the helmet (shown in FIG. 7). Disposing the shock absorbers between the outer shell and a single inner surface or a plurality of inner surfaces, would allow for air to travel within the helmet (around the shock absorbers and between the outer shell and inner surface(s)) (as illustrated in FIG. 7).

With reference to FIG. 12 an exemplary shock absorber is identified at reference numeral 500. Shock absorber 500 includes a bladder 502 circumscribed by a reservoir 504. Bladder 502 includes a wall 506 defining an internal cavity 508. Wall 506 includes a first portion 510 having a frustoconical shape extending along a longitudinal axis 512 in a first direction in relation to reservoir 504. Bladder 502 may also include a second portion 514 shaped as a mirror image of the frustoconical first portion. Second portion 514 extends along axis 512 in an opposite second direction in relation to the first direction. It should be appreciated that second portion 514 is optional and shock absorber 500 may include only first portion 510. Bladder 502 may be made from a high-strength fabric or a collapsible plastic wall. Alternatively, bladder 502 may be constructed from an elastomeric material.

Reservoir 504 is constructed from a material that need not be the same but may be the same material as reservoir 504. Reservoir 504 includes a first annular surface 516 and an opposite second annular surface 518. A reservoir cavity 522 is at least partially defined by first annular surface 516 and second annular surface 518. A plurality of circumferentially spaced apart orifices 524 place internal cavity 508 in fluid communication with reservoir cavity 522. It is envisioned that shock absorber 500 is filled with fluid with a vast majority of the fluid being positioned with internal cavity 508. At the time in which shock absorber 500 is installed within a helmet or similar device, reservoir cavity 522 is substantially void of fluid or contains fluid sufficient to fill the reservoir when it is at its smallest volume. First portion 510 of bladder 502 includes a planar first surface 530. Similarly, second portion 514 includes a planar second surface 532. During operation of shock absorber 500, a load or loads may be applied to one or both of first surface 530 and second surface 532. At this time, the volume of internal cavity 508 is reduced and fluid therein is forced to pass through orifices 524. As fluid passes through the orifices, energy is converted to heat and shock absorber 500 acts as a shock absorber. Fluid continues to flow into reservoir cavity 522. Based on the flexible nature of first annular surface 516 and second annual surface 518, fluid may be received within reservoir cavity 522.

In certain configurations, reservoir 504 may be configured to contract after the load to bladder 502 is released. Alternatively, bladder 502 and reservoir 504 may be configured to contain fluid within reservoir cavity 522 after the fluid passes through orifices 524. In such embodiments, the reservoir may serve to ensure that the fluid may continue to be used to dissipate impact energy but also ensuring that does not exit shock absorber 500.

In an alternate embodiment, shock absorber 500 does not include orifices 524. Energy of an impact to bladder 502 may be converted to heat by expansion of wall 506, and/or a permanent rupturing of bladder 502 to allow the fluid the flow outside of shock absorber 500. Energy is dissipated if the reservoir wall expands and contracts.

It should be appreciated that the frustoconical shape of first portion 510 and second portion 514 is merely exemplary. It is envisioned that outer wall 506 may define any number three-dimensional shapes including a cylinder, a sphere, rectangular prisms, or other geometrical shapes including elliptical cylinders. The cross-sectional shape of bladder 502 may be shaped as a hexagon, an octagon, a circle, a square or may be customized into any shape desirable to provide a desired fit or impact performance.

With the reference to FIG. 13, an alternate embodiment shock absorber is identified at reference numeral 550. Shock absorber 550 includes a first bladder 552, a second bladder 554, a third bladder 556, and a fourth bladder 558. In this embodiment, each bladder is sized and shaped substantially similarly to the others. It should be appreciated that this need not be the case. Each of first through fourth bladders 552, 554, 556, 558 are in fluid communication with a common reservoir 560. In one embodiment, it is envisioned that the reservoir is constructed from an elastomeric material that facilitates a change of volume defined therein. In the arrangement depicted in FIG. 13, first bladder 552 is in fluid communication with reservoir 560 via a first orifice 564. A second orifice 568 interconnects second bladder 554 with reservoir 560. A third orifice 570 fluidly interconnects third bladder 556 with reservoir 560. Lastly, a fourth orifice 572 allows fluid to pass therethrough fluidly interconnecting fourth bladder 558 with reservoir 560. Each of the bladders, 552, 554, 556, 558 and reservoir 560 may be mounted on an inner shell 574. inner shell 574 may be shaped specifically to provide comfort and well fitment to a wearer's head or other part of body where the device will be worn. Alternatively, the bladders and common reservoir may be mounted on an intermediate plate, the outer shell, or may be positioned within pockets formed in a carrier positioned between the inner shell and the outer shell.

In other embodiments, the reservoirs need not be fluidly connected. In these embodiments portions of one of the bladders or one of the reservoirs may be displaced during loading to contact a portion of another bladder or reservoir. A load transfer between the elements may occur. Alternatively, additional structures such as lengths of fabrics, strings, cables or elastic elements may interconnect bladders or a bladder and the reservoir to one another. The connection of the bladders to one another may be beneficial in that the relative position or arrangement of the bladders to one another may be more easily maintained during and after loading. In certain embodiments, fabric strips, strings, cables, or elastic elements interconnecting the bladders to one another may dissipate energy as they are stretched or compressed during loading of the bladders during an impact event.

As depicted in FIG. 14, an alternate embodiment helmet 600 includes an outer shell 602, an inner shell 604, a carrier 606, shock absorbers 608, and an inner liner 610. An optional inner shock absorber 612 is also shown. It should be appreciated that carrier 606 has been previously identified as a “layer of foam” or possibly an “inner surface.” Usage of the term “carrier” throughout the remainder of the application also applies to the previously described embodiments such that the phrase “inner surface” or “layer of foam” may be used interchangeably with the term “carrier”.

Various embodiments of helmets incorporating one or more shock absorbers 608 and carrier 606 are envisioned. FIG. 14 provides an exploded perspective view of one arrangement. Outer shell 602 is constructed from a substantially rigid material such as a thermoplastic as previously described. Shock absorbers 608 are configured as fluid-filled shock absorbers such that a force applied to the shock absorber is counteracted by an internal resistance to fluid flow and a change in shape such that energy input to the shock absorber is converted to heat and not merely transferred therethrough.

The type of fluid used in the shock absorbers may be selected to match the application in which the shock absorber will be used. It may be beneficial for energy dissipation that the fluid be an incompressible liquid. Furthermore, if being used in an application such as helmets or other personal protective equipment, it may be beneficial to select a fluid that is biocompatible in case the fluid leaks and spills onto a user. Fluids including water, propylene glycol, mineral oil, or other oil-based fluids may be useful in ensuring that contact with skin or ingestion of small amounts of the fluid will not cause harm, injury, or illness. Other applications may benefit from use of a hydrogel. Other embodiments may make use of a gas, such as air or nitrogen. Furthermore, other applications may benefit from use of a fluid that has a low freezing point.

Use of fluids that have a low freezing point ensures that the fluid will not turn to a solid during use in particularly cold environments. In several embodiments, it would be beneficial to use a fluid that has a freezing point below −28° C., as many helmet test standards, such as ASTM F2040 use this temperature or temperatures near to it for conditioning purposes. Using a fluid with a freezing point at or below −52° C. may also be beneficial in some applications, in accordance with military helmet test standards such as AR/PD 10-02. In general, the overall structure of the helmet or other protective device that includes the fluid-filled shock absorber should be able to withstand these low temperatures.

With continued reference to FIG. 14, carrier 606 includes a plurality of apertures 609 extending therethrough. The size, position, and orientation of each of aperture 609 assists in maintaining a desired position of each shock absorber 608 prior to, during and after use of helmet 600. Carrier 606 may be constructed from a wide variety of materials including foam. In some embodiments, the range of the density of the carrier foam may be from 10 kg/m³to 200 kg/m³. The foam may be an ethylene-vinyl acetate (EVA) foam, polyurethane foam, an expanded polypropylene (EPP) foam, neoprene, polyethylene, or an expanded polystyrene foam (EPS), for example. A variety of open-cell or closed-cell foams could be used.

Carrier 606 may alternately be comprised of a material other than foam in some embodiments. For example, a 3D printed lattice structure may fill some or all of the gaps between the shock absorbers and serve to both attenuate impact energy and also hold the shock absorbers in a desired orientation. It should be appreciated that not all helmets will be equipped with inner shock absorber 612 or inner shell 604.

The material comprising the carrier or carriers may have rigid connectors that allow them to connect to each other or to the helmet shell or to the inner shell. In some embodiments, the rigid connectors may extend from the carrier or carriers to touch the helmet shell without being connected to it. In other embodiments, the rigid connectors may extend from the carrier or carriers to nearly touch the helmet shell at rest, but only make contact with the helmet shell upon impact. These rigid connectors may be comprised of the same material as the carriers (such as EPS foam) or from a different material. The rigid connectors may also be made from a material that is the same as the helmet shell (such as carbon fiber, ABS plastic, polycarbonate, HDPE, or others). When the helmet is at rest or being worn, the rigid connectors will maintain the positioning and orientation of the carrier, shock absorbers, and helmet shell in a desired manner. When a force is applied to the helmet, the rigid connectors will keep the positioning and orientation of the carrier, shock absorbers, and helmet shell in a desired manner. When a force is applied to the helmet, the rigid connectors may break or decouple from the helmet shell or carrier, allowing the inner surface and helmet shell to move independently from one another. The physical breaking of the rigid connectors or their decoupling from the carrier or helmet shell may also serve to attenuate impact energy. In such embodiments, the rigid connectors enable the secure fitting of the helmet at rest, but improved energy absorption upon impact. In other embodiments, the carrier and shock absorbers may be held in place within the helmet shell by friction. At high enough impact force, the friction will be overcome, and the shock absorbers will shear while the helmet shell and carrier move independently.

FIG. 15 depicts another alternate embodiment helmet at reference numeral 600a. Helmet 600a is substantially similar to helmet 600. Accordingly, similar elements will be identified with like numerals including a lower “a” suffix. Helmet 600a includes a plurality of shock absorbers 608a positioned between an outer shell 602a and a carrier 606a. Each shock absorber 608a includes a pad 614a positioned adjacent to and in contact with an inner surface 616a of outer shell 602a. Carrier 606a includes a plurality of pockets 618a spaced apart from one another. An aperture 620a interconnects each pocket 618a with a cavity 622a located between inner surface 616a of outer shell 602a and an outer surface 624a of carrier 606a.

Shock absorber 608a includes a bladder 626a, a reservoir 628a and a conduit 630a interconnecting bladder 626a and reservoir 628a. Conduit 630 may be sized and shaped to function as an orifice. Alternatively, conduit 630a may be sized and shaped to function as pipe with orifices connecting the flow between the bladder 626a and reservoir 628a. The orifices in conduit 630a may be the same or different sizes as the diameter of the length of conduit 630a. Furthermore, conduit 630a may vary in diameter or shape throughout its length. Bladder 626a is preferably formed from a high-strength fabric that is collapsible and resistant to stretching or elongation. Reservoir 628a may be formed from an elastomeric material such that bladder 626a may deform and reduce in volume when an external force is applied outer shell 602a. The applied force causes fluid within bladder 626a to pass through conduit 630a and enter reservoir 628a. At this time, the interior volume of reservoir 628a increases to store the fluid that was previously positioned within bladder 626a. It should be appreciated that an outer surface 634a of reservoir 628a is spaced apart from walls 636a of pocket 618a. The response characteristics of each shock absorber 608a may be tuned based on the geometrical characteristics of reservoir 628a and pocket 618a. If walls 636a are relatively closely positioned to outer surface 634a of reservoir 628a, the reservoir 628a will be easily filled with fluid from bladder 626a until outer surface 634a contacts walls 636a. Once reservoir 628a contacts walls 636a, a substantially greater resistance to fluid flow from bladder 626a to reservoir 628a will occur. FIG. 15 provides an example with a pocket 638a being sized differently than pocket 618a.

The shape of reservoir 628a may also aid to hold shock absorber 608a in place within helmet, such that reservoir 628a is larger than the diameter of aperture 620a and therefore cannot be removed from pocket 618a unless by increased or intentional force. However, in some embodiments, reservoir 628a may have the same diameter as conduit 630a. In such embodiments, reservoir 628a may appear simply as an extension of conduit 630a that is simply not surrounded by or making contact with carrier 606a but instead resides in pocket 618a. Shock absorber 608a may be able to be removed in such embodiments, or others, if desired by a user after damage, failure, or if a user simply desires to upgrade or exchange the shock absorber 608a to a new shock absorber of the same or different design.

Carrier 606a may be constructed from a material such as EPS or EPP foam. Alternatively, carrier 606a may be made from another foam or material intended to attenuate impact force. It is envisioned that a radial extent or thickness of carrier 606a may range from 4 mm to 40 mm based on the particular application. Depending on the number of shock absorbers utilized in a given helmet and the size of the associated shock absorbers 608a, an inner diameter of apertures 620a may range from 2 mm to 20 mm in diameter. It should be noted that the embodiment depicted in FIG. 15 may be equipped with an inner shell such as inner shell 604 depicted in FIG. 14 or this component may be absent from helmet 600a.

The decoupling of helmet components layers has proven effective for reducing rotational motion of the head. The bladder of the fluid-filled shock absorbers 54, 104, 154, 208, 302, 352, 400, 458, 500, 550, 608, 608a, 608b, 608c, 608d, 644e, 645e, 646e, etc. may be comprised of a material that has a low shear modulus and allows for the bladder to shear when being compressed. The bladder may be constructed from a fabric such as nylon, Kevlar, polyester and other examples or may be constructed from an impermeable film, such as polyurethane. The shell of the helmet can move independently of the carrier and the inner shell, if present. In some embodiments, the outer shell or the inner shell may connect to the shock absorbers with an adhesive or rigid fastener. This connection to the shock absorbers allows for the independent motion of the inner or outer shell with respect to the carrier and is dependent on the compression and shearing of the shock absorbers.

FIG. 16 depicts another alternate embodiment helmet at reference numeral 600b. Helmet 600b is substantially similar to helmet 600a. Accordingly, similar elements will be identified with like numerals including a lower “b” suffix. In essence, helmet 600b switches the position of bladders 626a from a cavity formed between outer shell 602a and carrier 606a to a cavity 622b formed between inner shell 604b and an inner surface 642b of carrier 606b. The remaining features of carrier 606a are also present in carrier 606b, namely pockets 618b, apertures 620b, and outer surface 624b. In this embodiment, outer surface 624b of carrier 606b is positioned adjacent to and in contact with inner surface 616b of outer shell 602b. An optional inner liner may be positioned on inner shell 604b, if desired. FIG. 16 depicts another variant in which a pocket 619b is formed in carrier 606b. Pocket 619b extends completely through carrier 606b as a bore having any number of cross-sectional shapes.

FIG. 17 illustrates another alternate embodiment helmet at reference numeral 600c. Helmet 600c includes similar components as previously described in relation to helmet 600a and helmet 600b. As such, similar elements will retain like reference numerals including a “c” suffix. Helmet 600c includes an outer shell 602c having an inner surface 616c, a plurality of shock absorbers 608c, and a carrier 606c. Carrier 606c includes a plurality of apertures 609c extending therethrough. Shock absorber 608c includes a central bladder 626c and an annularly shaped reservoir 628c. Depending on the response characteristics desired, a plurality of orifices (not shown) may or may not be present within passageways that fluidly interconnect bladder 626c to reservoir 628c. Reservoir 628c is positioned between carrier 606c and inner surface 616c of outer shell 602c.

FIG. 17 depicts carrier 606c at an unloaded, relaxed position. At this position, carrier 606c exhibits a first thickness T₁. It may be preferable for the carrier foam to be oversized and low in density such that its thickness T₁at rest causes an opening in the underside of the helmet to be smaller than a user's head. When a user inserts their head into the helmet's opening, the low-density carrier foam will compress to thickness T₂and take the shape of a user's head. This enables a more comfortable fit of the helmet when worn to the head and reduces engineering costs associated with determining the appropriate size of the helmet's inner geometry for fitting to various head sizes. In such embodiments, the carrier foam may be between 1 mm and 20 mm greater in height than the shock absorbers themselves when carrier 606c exhibits the first thickness T₁.

Furthermore, carrier 606c may serve to restrict expansion of reservoir 628c or bladder 626c. In such cases, carrier 606c compresses when reservoir 628c is filled with fluid during an impact. After the impact force is removed from the protective device, carrier 606c expands and compresses reservoir 628c. Fluid is pushed from reservoir 628c back through the orifice, if present, and into bladder 626c readying shock absorber 600c for another impact. Additionally, bladder 626c may expand during an impact and compress carrier 606c in the lateral direction.

FIG. 18 provides a top view of another alternate embodiment helmet 600d with the outer shell removed. Carrier 606d includes a recess or valley 644d. Recess 644d may extend along an arc length more than half the circumferential extent of carrier 606d. Each shock absorber 608d includes a bladder 626d positioned within recess 644d. In a manner substantially similar to the arrangement depicted in FIG. 17, each shock absorber 608d includes a central bladder 626d and a reservoir 628d circumscribing centralized bladder 626d. A plurality of conduits 630d are circumferentially spaced apart from one another to fluidly interconnect centralized bladder 626d with reservoir 628d.

FIG. 19 depicts yet another alternate embodiment helmet at reference numeral 600e. This embodiment differs from the others in that inner shell 604e has a variable spacing between outer shell 602e. It is envisioned that shock absorbers 644e, 645e, 646e have different heights than each other. The height of each shock absorber matches the spacing between inner shell 604e and outer shell 602e. By varying the height of the fluid-filled shock absorbers, the response characteristics of the helmet may be tuned based on shock absorber location. At zones of expected high impact magnitude, the largest shock absorber 646e would be present. At other locations, a lesser magnitude impact may be expected and smaller shock absorbers such as shock absorber 644e may be positioned at these locations. An overall improvement in performance and reduction in helmet weight occurs.

In the helmet 600e depicted in FIG. 19, it is envisioned that inner shell 604e may rotate relative to outer shell 602e to reduce torsional load applied to a user's head. FIG. 20 depicts helmet 600e, initially shown in FIG. 19, in a torsionally loaded position during an impact. It should be appreciated that the concepts discussed in relation to a torque being applied to outer shell 602e also apply to every other embodiment described in this document. During application of an external torque such as during an impact, outer shell 602e is urged to rotate relative to an inner component of helmet 600e. As previously mentioned, the innermost member may be inner shell 604e. Relative rotation may occur between outer shell 602e and any one of the carriers previously described. Depending on the vector of the external force and the position of the particular shock absorber, the force applied during an impact may impart a shear load, a torsional load, and/or a radial load (compressive or tensile) to shock absorbers 644e, 645e, 646e.

To dissipate the energy when a torsional or shear load is applied to one or more of the shock absorbers, the shock absorbers may be coupled to the surrounding structure as previously described or as described below. For example, shock absorber 645e includes a distal end 647e that may be fixed to or in biased contact with an inner surface 616e of outer shell 602e. Shock absorber 645e includes a proximal end 648e that may be fixed to inner shell 604e or fixed to or at least positioned in contact with and restrained by any one of the carriers previously described. During the application of an external force that generates torque, some of the shock absorbers are placed in shear loading. In the embodiment depicted in FIG. 20, the shock absorbers do not rupture but maintain fluid therein. The construction of the shock absorber allows a leaning or shifting of the walls as depicted. A transfer of fluid between the bladders and reservoirs of the shock absorbers may also occur during shear loading to dampen the energy of the impact event and minimize the torque transferred through the shock absorbers to the inner shell or the carrier. As another nonlimiting example shown in at least FIG. 16, torsional or shear loading may be dissipated in helmet embodiments that have shock absorbers affixed to or in contact with the inner shell but spaced apart from the outer shell. Additionally, if the torque applied to any one of the previously described helmets generates a torsional load on a shock absorber, the bladder and/or reservoir may twist without rupture. However, the shock absorbers could be designed such that at a predefined load, they would rupture and provide additional impact attenuation benefit upon rupturing. Such a rupturing could also signal to the wearer of the helmet that the helmet or one or more of its components require replacement.

It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. Further, references throughout the specification to “the invention” are nonlimiting, and it should be noted that claim limitations presented herein are not meant to describe the invention as a whole. Moreover, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.

	Number	Date	Country
Parent	18378922	Oct 2023	US
Child	18975665		US

Lightweight Integration Of Shock Absorbing Technology In A Protective Device

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