The present invention relates to embodiments of lateral displacement shock absorbing technology and applications thereof. The present invention relates to a new way to attenuate impacts using tubular structures having non-uniform wall cross-sections preferably placed with their axes of elongation parallel to the direction of impact.
The objective achieved through operation of an impact attenuating material is absorption and dissipation of energy. This is accomplished when one object impacts another by slowing down the movement of the first object in a controlled manner. During the process of energy absorption, the impact attenuating material is compressed.
The degree of impact absorption achievable by an impact attenuating material is directly related to the difference between the pre-impact thickness and the thickness of the material when compressed to the maximum degree. Impact absorbing materials known in the prior art such as expanded polystyrene, expanded polypropylene, air bladders, and others bottom out when the input energy exceeds the ability of the impact absorbing material to further deform or crush. When the material bottoms out, further compression does not occur and, once bottoming out occurs, all of the further benefits of impact attenuation are gone.
For example, in the case of a material having a nominal pre-impact thickness of one inch, the material bottoms out with a thickness of 0.35 inches. Thus, only 0.65 inches of the material or 65% of it participate in the attenuation process. The remaining distance (0.35 inches) consists of the material stacking up and getting in its own way.
The science concerning use of impact attenuating materials to absorb energy is well known. Generally speaking, by varying the density and thickness of any given impact attenuating material, differing amounts of energy are capable of being absorbed. The challenge facing designers of impact attenuating products is to appropriately balance the criteria of thickness, stiffness, configuration, i.e., flat, arcuate, etc., and energy absorbing characteristics of a product so that the product is effective structurally, cost effective, as well as commercially viable. Thus, for example, numerous impact attenuating materials might be effective in attenuating impacts on an athlete wearing a helmet. However, if the initial thickness of the impact attenuating material is too high, this requires the helmet to be made with an outer shell that is too large in dimensions to be commercially viable regardless of the price or efficiency of impact attenuation.
Additionally, there is a need for impact attenuating materials that conform to surfaces of varying configurations, such as flat surfaces as well as arcuate or somewhat spherical surfaces such as found within a helmet.
Generally speaking, consumers demand relatively smaller and lighter products. Thus, in an athletic helmet, it is important to conform the outer shell of the helmet as closely as possible to the head of the athlete and for the impact attenuating materials to work effectively in that environment.
Helmet designers typically attempt to design a helmet that will reduce the risk of a broad range of injuries from mild traumatic brain injury (MTBI) to death, and for use in a wide range of activities such as from baseball to lacrosse to football to motor sports. The designers attempt to anticipate the kinds of impact energies that are most likely to occur and to design the helmet to preclude or at least minimize the likelihood of serious injuries from such impacts. The challenge in designing such a helmet is, again, to manufacture the helmet in a size that most optimally conforms to the size of the head that is to be protected thereby. Helmet designs are necessarily a compromise. Impact attenuation is tuned to absorb the type of energy that is most likely to result in permanent or catastrophic injury as a result of a specific activity. Thus, for example, motorcycle helmets are made extremely stiff because they are tuned to attenuate high energy impacts that result from road crashes. By contrast, football helmets are designed “softer” because they are tuned to the energy that results from players colliding together.
To achieve the combination of attenuation of both life threatening and non-life threatening energy levels, a helmet would have to be 1.5 to 2 times the thickness of one that was designed to only protect from life threatening events. A helmet designed to protect a user from MTBI events and not intended to address higher life threatening energies would be thin, but would be seen as unacceptable to the user because it would not adequately reduce the risk of catastrophic injury or death.
In order to achieve a broad range of input energies, the impact attenuating material must be made extremely thick. If a helmet designer chooses to design a helmet intended to absorb high energy impacts, a high density material would be used. If the same designer desired to achieve low energy absorption, a low density material would be employed. If the designer intended to achieve high and low energy absorption, thick materials would be required. All of these parameters and criteria are factored together and a suitable compromise is achieved for each intended activity and the required protection from impacts that typically occur when engaged in such activity.
Additionally, the particular configuration of the impact attenuating materials may have a bearing on its effectiveness.
The present invention relates to embodiments of a lateral displacement shock absorbing technology and applications thereof.
The present invention includes the following interrelated objects, aspects and features:
(1) In a first aspect, the present invention contemplates a structure consisting of a plurality of elongated tubular impact absorbing members, each having an axis of elongation. The axes of elongation of the respective tubular members may be parallel to one another. The tubular members are held together by virtue of web means or webbing, laterally extending from the sides of each tubular member, and interconnecting them together.
In one variation, the web means or webbing retains the tubes or tubular members with their axes in parallel relation. In other variations, the webbing may be slotted at the top, bottom, or both, to allow the respective axes of the tubular members to be in other than parallel relation. Such a configuration may be extremely useful where the inventive impact attenuating materials are installed within a helmet having a generally spherical configuration. By permitting the axes of adjacent tubes or tubular members to be other than parallel with one another, each tube can have its axis perpendicular to a tangent of the surface of the helmet at that location to more effectively attenuate impacts.
(2) Each of the tubular members, in the preferred embodiment, consists of an outer surface made up of two frustoconical surfaces with their larger diameter ends abutting one another and their smaller diameter ends facing away from one another. Each tubular member includes a passageway therethrough defined by two frustoconical shapes with the smaller diameter ends abutting one another, and the larger diameter ends facing away from one another and defining the openings of each passageway. The outer surfaces of the tubular members may, if desired, be ribbed.
(3) In considering a frustoconical surface, by definition, that surface is tapered. In accordance with the teachings of the present invention, the range of taper of the outer surface of each tubular member is from 1 to 45 degrees.
(4) While the preferred embodiment of the present invention contemplates tubular members having a circular cross-section, other cross-sections are suitable for use in accordance with the teachings of the present invention. Thus, polygonal cross-sections such as square, pentagonal, hexagonal, octagonal are equally usable as the cross-sections for the tubular members as are elliptical and non-polygonal, so long as the concept of an elongated tube with a central passageway is retained.
(5) The inventive material may be made of any desired effective material such as, for example, thermoplastics including polypropylene, urethanes, and rubber, foam materials such as foamed polyethylene.
(6) In operation, upon impact, the side walls of the tubular members bulge or displace laterally to absorb impacts. The taper of the walls and the open space within the tubular members allow the energy absorbing material to displace laterally allowing a greater range of travel, thus allowing a designer to use less material to obtain equally effective attenuation as compared to traditional materials. A sheet of material according to the teachings of the present invention, with a 1/16″ side wall thickness is able to crush to a vertical thickness of ⅛″, giving active attenuation from full vertical thickness to ⅛″ crushed thickness.
(7) When the present invention is manufactured using resilient materials, the invention exhibits multi-impact characteristics. The side wall shape and design along with material selection cause the material to absorb and dampen the impact rather than acting like a spring and rebounding the energy. Dampened rebound is important so that the material does not act like a bouncing ball and just return the energy to the object being shielded from inputted energy.
(8) The fact that each tubular member is centrally open facilitates enhanced ventilation of an athletic helmet from outside the helmet to the location of the user's head. Airflow through the tubular members easily occurs to enhance ventilation and keep the interior of the helmet relatively cooler.
(9) In the preferred embodiment of the present invention, the degree of taper of the inner and outer surfaces of the tubular members consist of mirror images of one another. However, if desired, the tapers of the inner and outer surfaces of the tubular member may differ.
(10) The shock absorbing material may be manufactured using injection molding, casting, compression molding, match molding, drape molding or may be machined from a wide variety of thermoplastic, rubber, and foamed materials as well as metallic, composite and ceramic materials.
(11) In one application of the impact attenuation material of the present invention, particular sets of tubes held together by suitable webbing are provided in arrays of seven or ten tubes. Each array has opposed ends that have tabs extending laterally outwardly therefrom. Of course, each array may have only one tab if desired. In a situation in which a plurality of arrays are to be installed within a helmet, in one embodiment, a sheet of material cut into a desired pattern is also provided with a plurality of spaced slots or holes designed to receive the tabs of the arrays therethrough. In this way, the arrays may easily be installed on the sheet of material which may then be placed within a helmet so that the arrays are installed at the appropriate locations for most efficient fit on the wearer and most effective shock attenuation. In one embodiment, the sheet of material is transparent which helps assist in the installation process by allowing the installer to see through the sheet of material and into the helmet to best facilitate alignment of the sheet of material with the arrays of tubes affixed thereto during installation.
(12) In installing a plurality of arrays of tubes or tubular members within a helmet, once the tubes are installed in the helmet as mounted on the sheet of material with slots or holes in it to receive the tabs of the arrays, in one embodiment, a comfort liner may comprise a multi-density foam material placed over the exposed ends of the tubes to facilitate spreading forces impacting the helmet over a greater surface area and to preclude the ends of the tubes from directly impacting the head of the user. In a preferred embodiment, the foam material of the comfort liner preferably has a lower density near the head of the wearer and a higher density nearer to the exposed ends of the tubes to help protect the wearer's head from being impacted directly by the ends of the tubes.
(13) Alternatively, rather than attaching the sheet of material to the helmet shell with the tubes extending inwardly therefrom, this configuration may be reversed with the ends of the tubes directly contacting the inner surface of the shell of the helmet and with the piece of material interconnecting the arrays together being located more inward toward the head of the user. Once the arrays and the sheet of material are suitably installed within the helmet, the same foam material as described earlier is installed overlying the sheet of material holding the arrays in the proper relationship with respect to one another.
(14) In a further variation, instead of installing the arrays by inserting their opposed tabs into slots formed into a piece of material, the arrays can suitably be installed by laminating them directly to the foam material at the desired locations for preferred impact attenuation, thereby omitting the step of providing a piece of material to which the arrays are first assembled. Other suitable attachment means to affix the arrays of tubes to the foam material can include rivets as well as staples and adhesives, sonic welding and heat staking.
(15) Another alternative for affixing the arrays of tubes to a piece of material to facilitate assembly in a desired configuration can consist of providing holes in the opposed tabs of each array and providing the piece of material to which the arrays are to be affixed with upwardly extending stubs or rods sized to extend through the holes in the array tabs. In order to affix the arrays to the piece of material, a heating device such as a soldering iron can be employed to melt the ends of the stubs or rods so that they spread out and lock the arrays of tubes in assembled configuration. Some welding or heat staking can also be employed.
(16) Another alternative embodiment of the present invention consists of molding a multiplicity of tubes in a single molding operation in a large mold that molds all of the tubes for a single helmet at one time in the desired configuration including integrally forming with the piece of material that provides the desired spacing and orientation. Such a one shot molding operation replaces the need to assemble a plurality of arrays of seven or ten tubes onto a piece of material using any one of the techniques and means described above.
While a preferred configuration for each tube is as disclosed in parent application Ser. No. 11/229,626, published as US/2007/0083965 A1, other tube configurations may also be contemplated. Wall configurations consisting of a plurality of connected flat sides, convoluted configurations, and other non-uniform wall thickness configurations provide effective attenuation values as disclosed herein.
Accordingly, it is a first object of the present invention to provide embodiments of a lateral displacement shock absorbing material and applications thereof.
It is a further object of the present invention to provide such material including a multiplicity of tubular members having axes of elongation aligned with one another.
It is a further object of the present invention to provide such a material in which the axes of the tubular members are maintained in alignment by virtue of webbing material integrally formed with the tubular members.
It is a still further object of the present invention to provide such a material that enhances the degree of energy absorption of a helmet structure over all known energy absorbing materials in use for helmets and other headgear.
It is a yet further object of the present invention to provide such a material in a further embodiment thereof in which the tubes are not constrained to be maintained parallel with one another but, rather, can conform to arcuate and spherical shapes such as those encountered within a helmet or on body padding.
It is a still further object of the present invention to provide such a material assembled in arrays having one or more tab(s) to facilitate installation.
It is a still further object of the present invention to assemble arrays of tubes on a piece of material for installation in a helmet or on body padding.
It is a still further object of the present invention to provide a variety of means to assemble arrays of tubes to material for positioning them in appropriate locations and orientations including stubs that are subsequently melted, tabs and slots as well as integrally molding the arrays with the piece of material in a one shot operation.
It is a still further object of the present invention to provide applications including use of a foam piece interposed between the ends of the tubes and the head of the user.
It is a yet further object of the present invention to provide the tubes in shapes including outer surfaces other than frustoconical including use of flat and arcuate circumferentially adjacent sections as well as convoluted portions.
These and other objects, aspects and features of the present invention will be better understood from the following detailed description of the preferred embodiments when read in conjunction with the appended drawing figures.
a shows a close-up view of one array of impact attenuation material with a further means for attachment to foam material consisting of posts integrally molded with the foam material inserted through holes in the tabs of the array and then melted.
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The inventive tubular members 11 and webbing 13 are made of any suitable material such as thermoplastic, for example, polypropylene, urethanes, and rubber. The inventive device 10 may be made in an injection molding process, in a pressure molding process, by casting, drape molding or machining.
The cross-section of the tubular members is shown as circular in the Figures. However, if desired, that cross-section may be polygonal, including triangular, square, pentagonal, hexagonal and octagonal as several examples.
The taper of the side walls 27, 29, 21 and 23 allows the inventive material to have a variable tunable crush ability. Use of a double taper, inside taper, outside taper or any combination thereof may be used depending upon the particular situation. The example shown includes both inner and outer double tapers. In the prior art, multi-impact attenuation products typically exhibit non-uniform resistance to crush, require a high load to start the crush process, and commencement of the crush process is typically followed by a non-uniform collapse. Applicants have found that the present invention as contemplated allows for a softer initial resistance followed by an increase in crush resistance as the material is compressed, thereby exhibiting a somewhat uniform resistance throughout a wide range of crushing activity.
If desired, the inside walls of the tubular members may be slightly tapered as shown in the Figures to allow the materials to roll inside as they collapse, thereby giving a shorter, completely collapsed height to the product. In use, the tubular members absorb and dampen impact rather than acting like springs and do not rebound energy as is the case in spring-like materials. Through dampened rebound characteristics, the material does not act like a bouncing ball which just returns energy from the impacting object.
Enhanced consistency is achieved through the preferred manner of manufacture, namely, injection molding. The present invention with its tubular members open completely therethrough enhances ventilation of a helmet or body padding in which they are installed. Airflow through the tubular members and past the webbing is virtually unrestricted.
Through changes in the density and durometer of the material, impact absorbing characteristics can appropriately be modified. In the preferred embodiments of the present invention, the material exhibits a durometer in the range of 20 to 120 on the Shore A hardness scale. By shortening the widths of the webbing 13 and thereby locating the tubular members 11 closer together, enhanced impact absorption characteristics result so long as sufficient spacing between adjacent tubes is maintained to allow each tube to collapse in length while expanding radially outwardly without restriction. Applicants have found that as a result of use of the teachings of the present invention, impact absorption can be enhanced by a factor of 50 to 75% over known impact absorbing materials.
In the preferred embodiments of the present invention, the elasticity of the materials from which the tubular members are made may range between 5 and 2,000%. Applicants have found that use of multi-tapered walls such as those shown in
The webbing 13 can play a role in impact attenuation. Prevention of interference of the webbing 13 with impact attenuation may be accomplished by attaching web structures to one end of a tubular member 11 only, by attaching the webbing 13 at both ends of a tubular member 11, by attaching the webbing 13 the full length from the top to the bottom of the tubular member or any fraction of that length, by making the webbing 13 of a multi-part construction, or by making the webbing convoluted in shape such as, for example, with a S-shaped cross-section. Of course, one important factor is to design the webbing and tubular members so that the entire assembly may be molded in a substantially linear movement of tooling halves to minimize the cost of tooling.
Applicants have found that certain variations in the configurations of the tubes forming impact attenuation arrays achieve effective impact attenuation. Additionally, Applicants have developed a variety of ways to employ impact attenuation arrays in accordance with the teachings of the present invention, particularly in the environment of sporting helmets.
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The piece of material 80 consists of, in a preferred embodiment, a transparent material so that when the assembled arrays 60 and 70 are to be installed within a helmet, the installer can see through the material 80 to properly align the arrays 60 and 70 within the helmet. The material 80 includes a plurality of slots 81 which are located to receive tabs 65, 67, 75 and 77 to preliminarily locate the arrays 60 and 70 in a configuration such as shown in
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As such, an invention has been disclosed in terms of preferred embodiments thereof which fulfill each and every one of the objects of the invention as set forth hereinabove, and provide new and useful embodiments of lateral displacement shock absorbing material and applications thereof of great novelty and utility.
Of course, various changes, modifications and alterations in the teachings of the present invention may be contemplated by those of ordinary skill in the art without departing from the intended spirit and scope thereof.
As such, it is intended that the present invention only be limited by the terms of the appended claims.
This application is a Continuation-in-Part of application Ser. No. 11/229,626, filed Sep. 20, 2005.
Number | Date | Country | |
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Parent | 11229626 | Sep 2005 | US |
Child | 12659544 | US |