Protective helmet pad interface structure

Abstract

A shock-absorbing, protective interface pad structure usable between the shell of a helmet and the head of a helmet wearer including (a) an acceleration-rate-sensitive, viscoelastic core structure made of a product having substantially the same characteristics as at least one of Confor CF-42 or Confor CF-45 manufactured by EAR Specialty Composites in Indianapolis, Ind., and (b) a water-moisture-blocking, bidirectionally gas-permeable barrier layer spray-applied to and fully enclosing the core structure, made of the a product having substantially the same characteristics as the product manufactured, and designated V-2000, by Russell Products Company, Inc. in Akron, Ohio.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to a human-body(head) protective, cushioning helmet interface (shock-absorbing) structure, pad-like in nature, which is designed especially to combine with a rigid protective helmet-shell to protect a helmet wearer's head from a blunt-trauma-type impact injury. The proposed interface pad structure is formed of plural, cooperative elements and materials, specified with particularity herein, that, in addition to offering superior, and comfortable, blunt trauma impact protection, also significantly minimize, via the respective possessions of individual, and cooperative, fire-resistance capabilities, and in a situation where serious and dangerous fire exposure exists, the likelihood of combusting-pad-contributed (a) sustained-pad-combustion burn injury to a helmet wearer, and/or (b) sustained-pad-combustion, per se, damage to, and destruction of, the shock-absorbing functional characteristics of the interface pad structure itself. More particularly, the present invention relates to such an interface pad structure (a) which lacks any springy (spring-back or rebound) resiliency, (b) which possesses acceleration-rate (strain-rate)-sensitivity, (c) which is designed to be interposed the body and a cooperating rigid barrier structure such as a helmet shell worn on the head, and (d) which offers the important kinds of fire-resistance (also referred to herein as “fire-resistant”) performance mentioned above.

In the prior patenting history generally of the subject matter of the present invention, expressed in a number of filed and prosecuted patent applications which have directed attention to different important features and aspects of the invention structure and methodology, primary emphasis has been directed toward the important load-cushioning and shock-absorbing behavior of the invention. At this point in the now-progressing history of seeking patent protection for the subject invention, this present patent application adds to the field of previously furnished emphasis a focus on the important fire-resistant qualities and characteristics of the materials which are preferably, and which should be, chosen for use in forming the several components of the overall interface pad structure of the invention.

As will become apparent, we have chosen, and we have, in detail, identified herein, particular materials for these components, which materials, in addition to acting cooperatively to furnish the intended, significant shock-absorbing behavior of the invention, with the clear understanding that other specific materials possessing substantially the same shock-absorbing characteristics may be used, specific materials also carefully selected to provide two, very important fire-resistant capabilities, one of which is that each of these materials, when exposed to an external fire-ignition source, while igniting and (almost surely) burning so long as that source is immediately present, nonetheless self-extinguish very shortly after removal of such an external source. In other words, material has been selected for the structure of components of this invention which do not self-fuel their own destruction by burning. The other important capability associated with the mentioned materials selections involves the resulting, anti-combustion, cooperative, collective nature of these materials in the sense that no one of these materials is capable of acting as kindling requisite to promote and sustain ignition and burning of any one of the other materials. This non-kindling cooperative characteristic of the materials chosen herein turns out to be an extremely important characteristic which it is entirely independent of the “personal”, non-self-fueling, individual characteristic of each of the chosen materials.

Just as is true with respect to the understood opportunity for substituting materials which may be specifically different from those identified herein for the purpose of supplying necessary shock-absorbing behavior in the overall pad structure of the invention, so also is it true that other specific materials may be employed which, in the context of supplying appropriate shock-absorbing characteristics, further possess substantially the same fire-resistant characteristics lying in the two fire-resistance categories/capabilities just mentioned above.

For this reason, the present patent application focuses special attention on the very specific materials which have been identified herein for pad/component construction, with the understanding that this focus is intended to include “substitute” materials possessing substantially the same, respective, overall characteristics.

While there are many helmet applications wherein the structure of the present invention can offer distinct advantages, one preferred embodiment of the invention is described herein specifically in the setting of a military helmet, with respect to which the invention has been found to furnish particular utility. As is well known, this is a setting laced with potential blunt-impact, and associated fire, dangers.

To accomplish the unique shock-absorbing performance of the invention, the proposed interface pad structure features a core formed of an acceleration-rate (strain-rate)-sensitive, viscoelastic, load-cushioning foam material which must “breathe” in order to function effectively, yet which must also be guarded entirely against any influx of water moisture—an influx which could quickly disable the material's load-cushioning capabilities.

Guarding this core material against a water-moisture “attack” is a thin, spray-apply, continuous-surface, fully jacketing, fully moisture-blocking (yet gas permeable) barrier layer material. This barrier layer material forms an uninterrupted continuum, enclosing the inside-contained acceleration-rate-sensitive core material, and thus defining an absolute limiting boundary for the “flow” of any water moisture moving toward the core material from the outside. Notwithstanding this important water-moisture barriering the barrier layer material “breathes” gas (air) bidirectionally to accommodate required breathability of the core material—thus accommodating substantially uncompromised load-cushioning behavior by the core material.

Associated preferably, though not absolutely necessarily, with these two, just-mentioned cooperative materials is a moisture-wicking fabric material which is disposed either in a fully surrounding (enveloping) manner relative to the core-structure and barrier-layer materials, or at least on that side of the core-structure and barrier-layer materials which is to be disposed adjacent a helmet wearer's head.

As has been suggested above, set forth below herein in the detailed description of the invention are specific materials that have been found to be very suitable for the three, respective, component structures mentioned above.

Offering the fire-resistance behavior characteristic of the preferred interface pad structure of the present invention, the materials just set forth above, in addition to possessing, as chosen, the requisite mechanical characteristics that are associated with shock-absorbing and water-moisture managing, also possess, by choice, the two, independent and collaborative, earlier-mentioned fire-resistance behaviors, characteristics and capabilities. Each of these materials is a non-self-fueling material if ignited by an external fire source; and collectively, significantly, and surprisingly, none of these materials, quite independently of their respective, associated, non-self-fueling characteristics, acts as a fire-sustaining kindling to either of the other materials.

These specific, best-mode materials, as originally set forth in the foundation specification in the underlying history of this case, and therefore also set forth specifically in the present specification, definitively offer the above-mentioned fire-resistance qualities.

All of the respective, individual characteristics of the interface-pad-structure materials—mechanical and fire-resistant in natures—identified with specificity in this application, are publicly known characteristics which are present in commercially available products. In particular, these characteristics are made known by the respective manufacturers of the identified materials. The important, collaborative non-cross-kindling behaviors of our chosen materials, however, are not pre-known, and are definitively part of the surprising discovery associated with the present invention.

Other, respective, like materials, with like characteristics, are expected also to be employable in the practice, structure and functioning of the present invention.

Accordingly, the claims to invention in the present application are directed both to the pad interface structure of the invention expressed (a) in specific terms wherein the components of the structure are stated to be made expressly of the specific, commercially available materials identified in the instant specification, as well as (b) in terms of like materials which effectively possess substantially the same mechanical and fire-resistance qualities and characteristics.

All of the special features and advantages mentioned above that are offered by the present invention will now become more fully apparent as the description which follows below is read in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation (with certain portions broken away to reveal details of internal construction) of a military helmet whose shell is equipped, on its inside, with plural (seven in total number) pad-like cushioning (shock-absorbing) interface structure constructed in accordance with the present invention.

FIG. 2 is a side elevation (also with portions broken away to reveal details of internal construction) of the helmet of FIG. 1, on about the same scale as, and taken generally from the right side, of FIG. 1.

FIG. 3 is an enlarged-scale, fragmentary and partly cross-sectioned detail taken generally in the area of curved arrows 3-3 in FIG. 2, showing one of the several shock-absorbing interface pad structures of the invention pictured in the shell of the helmet shown in FIGS. 1 and 2.

FIG. 4 is a view illustrating a modified form of shock-absorbing interface pad structure constructed in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

Turning attention now to FIGS. 1, 2 and 3, indicated generally at 10 is a military helmet including a rigid shell 10a. In all respects, shell 10a is completely conventional in construction, and might have any one of a number of different specific constructions and configurations.

Fastened in one of a variety of appropriate manners on the inside, concave, dome-like surface of shell 10a is an installation 12 of shock-absorbing, load-cushioning interface pad structure constructed in accordance with the present invention. Installation 12, in the particular setting illustrated in these figures and now being described, includes seven, individual, multi-layer, shock-absorbing, interface pad structures, or pads, 12a 12b, 12c, 12d, 12e, 12f, 12g, each of which includes one preferred form of a central, load-cushioning, shock-absorbing core structure, or core, possessing certain characteristics which are key to the shock-absorbing functionality of the present invention. Pad 12a is joined to the inside surface of shell 10a in the frontal, central portion of that surface. Pads 12b, 12c are disposed on laterally opposite sides of pad 12a. Pads 12d, 12e are located in laterally spaced places on the inside, lower, rear portion of the inside surface of shell 10a. Pad 12f is positioned centrally between pads 12d, 12e. Pad 12g is disposed on the upper (or crown) portion of the inside surface of shell 10a.

It should be understood that the shapes and the locations of the illustrated seven pads, and indeed the specific number of pads chosen for use illustratively in helmet 10, are completely matters of choice, and form no part of the present invention. These specific shapes, locations, and this “pad-count” number, have been chosen, rather, in relation to picturing the equipping of the shell of helmet 10 with one appropriate deployment of the helmet pad interface structure of the invention. In terms of the features of the present invention, all seven pads shown associated with helmet 10 are essentially the same in construction. Accordingly, a detailed description of the construction of helmet pad interface structure 12a which now follows fully describes the construction of each of the other six pads in installation 12.

Thus, pad 12a includes a central load-cushioning, shock-absorbing core (core structure) 16 made up, in the embodiment of the invention which is now being described, of two, internally facially confronting, “stacked” core components 16a, 16b. This core structure lies at the heart of the shock-absorbing behavior, per se, of the present invention. Also included in pad 12a is a water-moisture-blocking, gas-permeable barrier layer 18, and optionally, a moisture-wicking outer layer 20 (fully enveloping, or “one-sided” only, as will be explained). The right side of pad 12a in FIG. 3 is referred to herein as its body-facing side, and the left side of the pad in this figure is referred to herein as its helmet-shell-facing side.

Each of core components 16a, 16b is formed of a suitable, acceleration-rate(strain-rate)-sensitive, viscoelastic material which possesses, in technical “terms” known to those skilled in the art, a behavior which responds to compressive acceleration in a manner that is likenable generally to the sheer-resistance behavior which is observed in certain fluids as a phenomenon known as fluid dilatancy. When compressive pressure is applied to these kinds of viscoelastic materials, if that pressure application is done at a very low acceleration rate, the materials respond very readily and fairly instantaneously with a yielding response. However, if such a pressure is applied rapidly, i.e., with a rapid acceleration rate, the materials tend to act very much like solids, and they do not respond rapidly with a yielding action. Generally speaking, the higher the rate of acceleration associated with an applied compressing force, the more like solid materials do components 16a, 16b, i.e., the collaborating core-structure components, perform.

An important consequence of this acceleration response characteristic is that the core structure of the present invention offers, in relation to prior art load-cushioning, shock-absorbing structures, a superior shock-cushioning, shock-absorbing action. It thus offers a significant improvement in relation to the prior art with respect to blunt-trauma injury avoidance.

A contributing factor also in this regard is that the materials in core structure 16, after undergoing a compressive deformation, return relatively slowly toward their pre-deformation configurations.

While there are, and may be, various appropriate acceleration-rate-sensitive materials that are employable in core structure 16, component 16a herein in this core structure is preferably made of the material designated Confor CF-42 made by a company called EAR Specialty Composites in Indianapolis, Ind. Core component 16b is preferably made of the material designated Confor CF-45, also made by this same company. Since the time of the original writing of the specification in this application, and in its predecessor applications, it is possible that the manufacturer of these two materials has changed the specific product designator of either or both materials, and it is intended that the specific product designators presented herein also be understood to refer respectively to product(s) possessing any such designation change(s).

Preferably, the overall thickness of core structure 16, i.e., the dimension thereof measured laterally (or from left to right sides) in FIG. 3 (shown at T₁), is about ⅞-inches. Component 16a alone has a thickness, pictured in FIG. 3 at T₂ (measured in the same fashion), of about ⅜-inches, and component 16b alone a thickness, pictured in FIG. 3 at T₃, of about ½-inches. Core components 16a, 16b are joined to one another by means of a suitable, interfacial adhesive.

Barrier layer 18 which completely surrounds, encapsulates and envelops core structure 16 in pad 12a is a sprayed-on layer formed of a vinyl-solvent-based material sold under the product designator V-2000 made by Russell Products Company, Inc. in Acheron, Ohio. In general terms, this coating product forms a smooth, vibration-resistant, skin-like protective layer over the outside surfaces (entirely) of core structure 16. It provides a breathable and durable, flexible membrane skin on the outside of the core structure, which skin completely blocks penetration, at any location, of water moisture into the core structure from the outside of the barrier layer. Notwithstanding this important, “continuity”, water-moisture barriering behavior, layer 18 permits relatively free bidirectional gas flow into and out of the core structure. Thus, it permits necessary “breathing” of core structure 16 under circumstances of compression and return-from-compression. Preferably, this barrier layer has a thickness somewhere in the range of about 0.007-inches to about 0.01-inches, and in the specific construction now being described, has a thickness of about 0.009-inches.

Full continuity “jacketing” of the core cushioning structure by the barrier layer enables an associated helmet, such as helmet 10, to be fully immersed in water, under most circumstances, without there occurring any appreciable degradation in core-material, acceleration-rate-sensitivity performance, which degradation would result from any water-moisture entrance into the acceleration-rate-sensitive core material.

The comment made above regarding manufacturer re-designating of a product is intended to be applicable as well to the identified barrier-layer material.

Jacketing and enveloping the outside of the combined assembly of core structure 16 and barrier layer 18 is a moisture-wicking layer 20. This layer, which is optional, is, when employed, preferably distributed somewhat in the form of an enclosure bag around the core structure and barrier layer. In the construction now being described, layer 20 takes the form of a polyester fabric (with a nominal thickness of about 0.015-inches) known as Orthowick, made by Velcro Laminates, Inc. in the Bristol, Ind. Specifically, this Orthowick material bears the product in designator Velcro® brand Loop 3993. The bag form of structure 20 herein is closed by stitching as indicated schematically by a short, dashed line 22 in FIG. 3. As can be seen, and importantly, this stitching does not penetrate the barrier layer.

The comments made above regarding manufacturer re-designating of products are applicable as well to the just-identified moisture-wicking layer material.

Pad 12a is suitably removeably attached to the inside of helmet shell 10a through a two-component, conventional, hook-and-pile structure 24 sold under the name Velcro—a readily commercially available product made by Velcro USA, Inc. in Manchester, N.H.

Turning attention now to FIG. 4, here there is illustrated a modified form 12a of a shock-absorbing interface pad structure usable in helmet 10 at the location, for example, of previously described pad 12a. In this modified pad 12a, core structure 16 includes but a single, acceleration-rate-sensitive, viscoelastic component 16c surrounded by a barrier layer 18, and additionally, a moisture-wicking layer 20 which is defined by but a single expanse of material 20a that extends (one side only) solely on and across what has been referred to previously as the body-facing side of pad 12a.

Component 16c has a thickness, indicated at T4 in FIG. 4, of about ½-inches, and is formed preferably of the above-mentioned Confor CF-42 material.

Completing, with moisture-wicking expanse 20a, an enclosure generally in a bag form around the assembly of core component 16c and barrier layer 18 is another expanse 26 of any suitable fabric material.

The specific materials set forth above which have been chosen for elements 16 (16a, 16b, 16c), 18, and 20 in the interface pad structure of the invention, in addition to possessing the several, important shock-absorbing and water-moisture-, and water-, managing characteristics already discussed, further possess, by intentional choice, individually, and cooperatively/collectively, important fire-resistance characteristics. These fire-resistance characteristics are such that each of these materials, when exposed to (and then thereafter de-exposed from) an external fire-igniting source, do not self-fuel continued self-combustion, and tend, therefore, to self-extinguish any combustion which may have begun. Most significantly, and indeed surprisingly, because of their respective, individual characteristics, these materials, as combined in the overall interface pad structure of the invention, do not cross-kindle one another. Such cross-kindling, of course, is a risk and a danger independent of the material's respective self-extinguishing behaviors. In other words, notwithstanding a particular material's individual ability to self-extinguish any started combustion, and to resist self-fueling, it is entirely possible for an adjacent, different material, if burning, to act as kindling (referred to herein as cross-kindling) for the nominally self-extinguishing-capable material, and thereby to defeat that material's self-extinguishing propensity.

These fire-resistant qualities of the specific materials chosen for incorporation in the interface pad structure of the invention are significant in relation to minimizing both (a) potential pad-created burn injury to a helmet wearer, and (b) the likelihood of combustion degradation of the important shock-absorbing performance of a pad structure's cushioning-core componentry. Without specifying anything more, preferred use of the herein-above-identified pad-structure materials assures this just-explained, resulting fire-resistance behavior. In this context, it will be understood that substantially the same fire-resistance performance will be obtained with selection and use of alternative, respective, pad-structure materials which possess essentially the same, respective, material-specific characteristics.

There is thus provided by the present invention a unique, shock absorbing, load-cushioning structure which offers the various compression-and-slow-return, non-springy, acceleration-rate(strain-rate)-sensitive, viscoelastic benefits ascribed to it hereinabove—which benefits offer significant blunt-trauma-injury resistance improvements over related prior art structures. The particular pad-component materials identified herein, and more pointedly the specific material characteristics of these materials, assure the important shock-absorbing and fire-resistance behaviors central to the performance features of the interface pad structure of invention.

While the invention has been disclosed in particular forms herein, numerous variations, some of which have been discussed, are recognized to be possible, and in this context, we regard the subject matter of our invention to include all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed herein.

Claims

1. A shock-absorbing, protective interface pad structure usable between the shell of a helmet and the head of a helmet wearer comprising an acceleration-rate-sensitive, viscoelastic core structure made of a product having substantially the same characteristics as at least one of Confor CF-42 or Confor CF-45 manufactured by EAR Specialty Composites in Indianapolis, Ind., anda thin and flexible, water-moisture-blocking, but gas-permeable barrier layer spray-applied to and fully enclosing said core structure, made of the a product having substantially the same characteristics as the product designated V-2000 by Russell Products Company, Inc. in Akron, Ohio, completely blocking outside access to the core of all water moisture while accommodating substantially free, bidirectional gas breathability by the core structure.

2. The interface pad structure of claim 1 which possesses a body-facing side intended to face a helmet-wearer's head, and which further comprises an expanse of a moisture-wicking material made of a product having substantially the same characteristics as the product sold as Orthowick designated VELCRO® brand Loop 3993 by Velcro Laminates, Inc. in Bristol, Ind., with said expanse having a configuration which is one of (a) substantially completely enveloping the barrier-layer enclosed core structure, or (b) disposed across said pad structure's said body-facing side.

3. A shock-absorbing, protective interface pad structure usable between the shell of a helmet and the head of a helmet wearer comprising an acceleration-rate-sensitive, viscoelastic core structure made of at least one of the product designated Confor CF-42 or Confor CF-45 manufactured by EAR Specialty Composites in Indianapolis, Ind., anda thin and flexible, water-moisture-blocking, but gas-permeable barrier layer spray-applied to and fully enclosing said core structure, made of the product designated V-2000 by Russell Products Company, Inc. in Akron, Ohio, completely blocking outside access to the core of all water moisture while accommodating substantially free, bidirectional gas breathability by the core structure.

4. The interface pad structure of claim 3 which possesses a body-facing side intended to face a helmet-wearer's head, and which further comprises an expanse of a moisture-wicking material made the product sold as Orthowick and designated VELCRO® brand Loop 3993 by Velcro Laminates, Inc. in Bristol, Ind., with said expanse having a configuration which is one of (a) substantially completely enveloping the barrier-layer enclosed core structure, or (b) disposed across said pad structure's said body-facing side.