U.S. patent application number 11/096695 was filed with the patent office on 2005-08-04 for non-resiliency body-contact protective helmet interface structure.
This patent application is currently assigned to MJD Innovations, L.L.C.. Invention is credited to Dennis, Michael R..
Application Number | 20050166302 11/096695 |
Document ID | / |
Family ID | 37073770 |
Filed Date | 2005-08-04 |
United States Patent
Application |
20050166302 |
Kind Code |
A1 |
Dennis, Michael R. |
August 4, 2005 |
Non-resiliency body-contact protective helmet interface
structure
Abstract
Shock-absorbing, load-cushioning interface structure for use
inside, and in operative cooperation with, the shell of a helmet
for operative interposition such a shell and the head of a wearer.
This structure is characterized with features and performances
including (a) compression-deformation-and-slow-return
viscoelasticity, (b) non-springy (anti-rebound) during a return
from deformation, (c) acceleration-rate(strain-rate)-sensitivity,
and (d) a durometer associated with an ILD number which is no less
than about 15-ILD.
Inventors: |
Dennis, Michael R.;
(Scappoose, OR) |
Correspondence
Address: |
ROBERT D. VARITZ, P.C.
4915 S.E. 33RD PLACE
PORTLAND
OR
97202
US
|
Assignee: |
MJD Innovations, L.L.C.
|
Family ID: |
37073770 |
Appl. No.: |
11/096695 |
Filed: |
March 31, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11096695 |
Mar 31, 2005 |
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10156074 |
May 27, 2002 |
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10156074 |
May 27, 2002 |
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09942987 |
Aug 29, 2001 |
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6467099 |
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09942987 |
Aug 29, 2001 |
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09390518 |
Sep 3, 1999 |
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60099208 |
Sep 3, 1998 |
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Current U.S.
Class: |
2/414 |
Current CPC
Class: |
B32B 3/26 20130101; F16F
9/30 20130101; B32B 3/04 20130101; B32B 2571/00 20130101; B32B
33/00 20130101; B32B 25/08 20130101; B32B 2307/724 20130101; B32B
25/04 20130101; F16F 2236/045 20130101; A42B 3/121 20130101; B32B
2307/7265 20130101; A42B 3/127 20130101 |
Class at
Publication: |
002/414 |
International
Class: |
A42B 003/00 |
Claims
I claim:
1. Shock absorbing structure for use inside the shell of a helmet
for operative interposition such a shell and the head of a wearer
comprising a load-cushioning instrumentality which is structurally
characterized with (a) compression-deformation-and-slow-return
viscoelasticity, (b) non-springy (anti-rebound) behavior, (c)
acceleration-rate(strain-rate)-s- ensitivity, and (d) a durometer
which is associated with an ILD number of no less than about
15-ILD.
2. The shock-absorbing structure of claim 1, wherein said
instrumentality is formed from plural, cooperative bodies of
materials each individually characterized as expressed for the
instrumentality set forth in claim 1.
3. Helmet structure, in operative condition comprising a shell, and
shock-absorbing structure installed in said shell, disposed therein
to act in a condition of operative interposition between said shell
and the head of a wearer of the helmet structure, and taking the
form of a load-cushioning instrumentality which is structurally
characterized with (a) compression-deformation-and-slow-return
viscoelasticity, (b) non-springy (anti-rebound) behavior, (c)
acceleration-rate(strain-rate)-s- ensitivity, and (d) a durometer
which is associated with an ILD number no less than about
15-ILD.
4. The helmet structure of claim 3, wherein said instrumentality is
formed from plural, cooperative bodies of materials each
individually characterized as expressed for the instrumentality set
forth in claim 3.
5. The helmet structure of claim 3, wherein said shock-absorbing
structure, within said shell, defines a load-transmission path
between said shell and the head of a wearer, in which path
compression deformation and return response to a shock load
delivered to the shell is solely determined by the characteristics
of said shock-absorbing structure.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part from currently
co-pending U.S. patent application Ser. No. 10/156,074, filed May
27, 2002 for "Body-Contact Protective Interface Structure and
Method", which application is a continuation from U.S. patent
application Ser. No. 09/942,987, filed Aug. 29, 2001, entitled
"Body-Contact Cushioning Interface Structure and Method", which is
a continuation from U.S. patent application Ser. No. 09/390,518,
filed Sep. 3, 1999, entitled "Body-Contact Cushioning Interface
Structure", which application claims priority to U.S. Provisional
Application Ser. No. 60/099,208, filed Sep. 3, 1998, entitled "Body
Contact System and Structure for Wearable Garments, such as a
Helmet." The disclosure contents of each of these prior-filed
patent applications are hereby incorporated herein by
reference.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The present invention relates to a human-body protective,
cushioning helmet interface (shock-absorbing) structure which is
designed especially to combine with a rigid protective helmet-shell
barrier structure to protect the head from a blunt-trauma-type
impact injury. More particularly, it relates to such structure (a)
which lacks any springy (spring-back or rebound) resiliency, (b)
which possesses acceleration-rate (syn., strain-rate)-sensitivity,
and (c) which is designed to be interposed the body and a
cooperating rigid barrier structure such as a helmet shell which is
worn on the head, and through which rigid barrier structure (shell)
and cushioning interface structure various kinds of shock loads may
be delivered. The invention also relates to a helmet structure per
se which includes a rigid barrier shell and cushioning interface
structure of the type just generally outlined.
[0003] 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.
[0004] From the important underlying disclosure history which
illustrates and describes the invention focused upon herein,
cross-referenced above in the forms of related cases, one
particular patent of special interest has issued. This patent, U.S.
Pat. No. 6,467,099, issued Oct. 22, 2002 for "Body-Contact
Cushioning Interface Structure", directs attention to an embodiment
of the invention which is a specifically designed for use in
environmental settings where moisture saturation, as by immersion
in water, could present a problem by entering the cushioning
structure material and diminishing the load-cushioning qualities of
that material per se which is directly responsible for effecting
non-springy, viscoelastic, acceleration-rate(strain-rate)-sensitive
response to an impact (shock) event. To deal with that
moisture-related issue, the embodiment of the invention featured
there includes a cushioning core structure suitably coated with a
gas-breathable, moisture-impenetrable barrier layer. The presently
focused-upon embodiment of the invention addresses another kind of
environmental situation wherein immersion moisture is not expected
to become a problem.
[0005] Very specifically, the present invention embodiment points
attention to the originally disclosed (in the underlying prior
patent applications) core load-cushioning structure per se, and the
direct cooperative relationship between that structure and a rigid
helmet shell, without necessary reference being made to the
presence or absence of a moisture-impervious outer barrier layer.
Even more specifically, the invention set forth herein focuses,
inter alia, on a special load-cushioning structure which is
intended for combinational assembly and performance directly with a
rigid protective-barrier helmet shell which first receives a shock
impact against which the invention is designed to protect. There is
no intervening, other load-handling structure interposed this
load-cushioning structure and a helmet shell, though, if desired,
the load-cushioning structure of the invention may be received in
an envelop structure which deals with moisture wicking and/or
attachment to a helmet shell. This load-cushioning structure
possesses important, combined "core characteristics" which include
(a) compression-deformation-and-slow-return viscoelasticity, (b)
non-springiness, (c) acceleration-rate(strain-rate)-sensitivity,
and (d) a durometer which is associated with an ILD (Identation
Load Deflection) number which is no less than substantially 15-ILD.
The invention also focuses attention on a helmet structure per se
whose outer shell is appropriately lined, or otherwise internally
equipped, with an insert, or inserts, of such load-cushioning
structure.
[0006] Thus, one should read and understand the presently addressed
invention by directing special attention toward the structure and
use, per se, of a material combinable directly with an outer, rigid
helmet shell, and interposable that shell and a wearer's head,
which structure is, collectively, non-springy, viscoelastic with a
minimum defined ILD number, and
acceleration-rate(strain-rate)-sensitive.
[0007] With reference to a conventional military helmet, such an
environment is vividly demonstrative of the issues that are
successfully addressed by the present invention. For example, the
current U.S.-issue military infantry helmet utilizes in its outer
shell an internal webbing system combined with a removable leather
liner to suspend the helmet on the wearer's head. Airspace between
the webbing and the shell of the helmet contributes somewhat to the
ballistic, and significantly to the cooling, capabilities of the
helmet, but such a webbing system has proven consistently (a) to do
a poor job of cushioning shock loads delivered to the wearer's head
through the subject helmet, and (b) to be quite uncomfortable, and
thus to be the source of many complaints from users.
[0008] The structure of the present invention offers appreciable
improvements in these areas of concern regarding helmet
performance. This structure, in the preferred form of the invention
described herein, features a novel cushioning structure which
offers the very important cooperative characteristics of
compression-deformation-and-slow-return viscoelasticity,
non-springiness, and what is known as
acceleration-rate(strain-rate)-sensitivity.
[0009] According to the invention, it features what is referred to
herein as a load-cushioning instrumentality formed from one, or a
plurality of, body(ies) of a material which responds
acceleration(strain)-rate-resistan- tly to shock-produced, rapid
acceleration, with a resistance to compression deformation that
generally rises in a somewhat direct relationship to the level or
magnitude of acceleration. This kind of
acceleration-rate(strain-rate)-sensitivity is somewhat analogous to
the phenomenon known in the world of fluid mechanics as
shear-resistant fluid dilatancy. This behavior, in the "world" of a
helmet shell, causes a shock load to be transmitted to, and borne
by, the wearer's head over a relatively wide surface area, and thus
generally reduces the likelihood of serious injury. The
rate-sensitive material proposed by the structure of this invention
also responds to (and following) an impact event by recovering
slowly from compression deformation to an undeformed
condition--thus avoiding any dangerous "rebound", spring-back
activity. In point of fact, the load-cushioning material employed
in accordance with the invention is decidedly non-springy in
character. As will be further mentioned, the load-cushioning
material proposed by the invention, in order to be capable of
dealing most effectively in direct combination with a rigid helmet
shell in the protection against head impacts, possesses a durometer
with a minimum ILD number of about 15-ILD.
[0010] The association which exists between the load-cushioning
structure and a helmet shell (rigid), is that the helmet shell
converts whatever kind of specific impact occurs to it from the
outside to a broad-area, blunt-trauma kind of event which is
delivered directly to the load-cushioning structure without there
being any interposed, other load-managing material, such as any
material with springy rebound (resilience) behavior. Such a
blunt-trauma event presented through the shell to the
load-cushioning structure takes maximum advantage of the cushioning
capabilities of the load-cushioning structure, and results in
significant anti-injury impact delivery to the head of a helmet
wearer.
[0011] With the load-cushioning (shock-absorbing) structure of this
invention incorporated for use in conjunction with an operatively
associated helmet shell, a load-transmission path exists between
that shell and the head of a wearer. In this path, compression
deformation and return response to a shock load delivered to the
outside of the shell is solely determined by the characteristics of
the invention's load-cushioning structure. Northing in this path
introduces any form of a springy, spring-back, rebound
response.
[0012] The structure of this invention is easily rendered in a
variety of specific configurations, and thus is readily usable in a
host of different helmet settings. It is relatively easy and
inexpensive to manufacture, and it can be introduced very
conveniently in a wide range of helmet "retrofit" situations. For
example, it can be employed within, and in conjunction with, a
helmet shell as a distribution of plural load-cushioning pads. It
can also be implemented, if desired, as a large, singular
helmet-shell insert. Overall structure thickness can be selectively
chosen to be different for different circumstances. A single, or
more than two, rate-sensitive sublayer(s) can be employed. Within a
relatively wide range set forth below herein, a different specific
durometer value (or values in a stack of sublayers) for the
rate-sensitive sublayer(s) can be chosen.
[0013] 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
[0014] FIG. 1 is a front elevation (with certain portions broken
away to reveal details of internal construction) of a military
helmet whose outer shell is equipped on its inside with plural
pad-like expanses (seven in total number) of cushioning interface
structure constructed in accordance with the present invention.
[0015] FIG. 2 is a side elevation (also with portions broken away
to reveal internal construction) of the helmet of FIG. 1, on about
the same scale as and taken generally from the right side of, FIG.
1, with load-cushioning structure which is contained within the
shell of this helmet being illustrated in a condition tilted
slightly toward the viewer in this figure.
[0016] FIG. 3 is an enlarged-scale, fragmentary detail taken
generally in the area of curved arrows 3-3 in FIG. 2, showing in
cross section one of the several load-cushioning interface
structures of the invention employed in the shell of the helmet of
FIGS. 1 and 2.
[0017] FIG. 4 is a view showing a modified form of load-cushioning
structure constructed in accordance with the invention.
[0018] FIG. 5 is a simplified view, somewhat like FIG. 2, showing a
single helmet-shell insert version of the load-cushioning structure
of the invention.
[0019] In FIGS. 3 and 4, but not in FIG. 5 wherein no ancillary
jacketing structure specifically appears, certain outside jacketing
structures (ancillary structures) for the illustrated
load-cushioning structures of the invention are shown.
DETAILED DESCRIPTION OF, AND BEST MODE FOR CARRYING OUT, THE
INVENTION
[0020] Turning attention now to FIGS. 1, 2 and 3, indicated
generally at 10 (FIGS. 1 and 2) is a military helmet including a
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.
[0021] 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 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,
load-cushioning, interface-structure pads 12a, 12b, 12c 12d, 12e,
12f, 12g, each of which includes one preferred form of a central,
or core, load-cushioning instrumentality possessing certain
characteristics which are key to the structure and 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.
[0022] With a brief digression made here to FIG. 5, this figure
shows an installation in helmet shell 10a which takes an
alternative invention form, one of many possible alternative forms,
of a single load-cushioning insert 14 which is employed instead of
plural, distributed pads. Insert 14 may be made to have the
internal structure of any embodiment of the invention.
[0023] With regard to configuring a load-cushioning instrumentality
as a singular insert for a helmet shell, as illustrated in FIG. 5,
such an embodiment is visually similar to, but functionally and
internally structurally very different from, a commercial product
known as Zetaliner.TM. made by Oregon Aero based in Scappoose,
Oreg. The Zetaliner.TM. product takes the form of a cloth-covered
viscoelastic foam insert for installation within a plastically
crushable, shell-like insert component which itself sits inside a
helmet shell. The foam is of very low durometer and ILD number,
less than 15-ILD, and is designed to create a tight, conforming and
deforming fit with a wearer's head. The foam is thus normally
substantially in a compressed and deformed state (to enhance fit)
when it is in use, and it is the immediate outer, crushable
shell-like insert which functions, non-reversibly, to respond with
shock dissipation of an impact delivered to the associated helmet
shell. The foam, in its normally substantially compressed and
deformed state, is not poised for load-cushioning. It functions
essentially for fitment purposes, rather than for load
cushioning.
[0024] Returning to FIGS. 1-3, inclusive, the perimetral shapes and
the locations of the illustrated seven pads, and indeed the
specific number of pads chosen for use in helmet 10 in this form of
the invention, are completely matters of choice, and are not part
of the present invention. These specific shapes, locations, and
this "pad-count" number, have been chosen in relation to equipping
the shell of helmet 10 with one appropriate and versatile, overall
interface structure that acts between a wearer's head and shell
10a. A description of a preferred internal construction for pad 12a
which now follows, fully describes the construction of each of the
other six pads in installation 12.
[0025] Accordingly, pad 12a includes a central, or core,
load-cushioning structure, or instrumentality, 16 made up of two
sublayers 16a, 16b. This core structure, viewed either individually
as something which can be installed inside the shell of a helmet,
or as part of a cooperative combination with the outer shell (10a)
of a helmet, lies at the heart of the present invention.
[0026] Ancillary to this load-cushioning core structure, but
nonetheless illustrated in FIGS. 1-3, inclusive, are an applied
moisture-blocking, gas-permeable barrier layer 18, and a
moisture-wicking outer layer 20. These two layers, while includable
if desired, are not part of the present invention. The earlier
mentioned, cross-referenced, historical background-case material
describes materials which could be used for these layers if one
chooses to include them.
[0027] Practical experience has shown that it is very useful, and
thus desirable, to include at least outer wicking layer 20 which,
while not affecting load-cushioning behavior, offers a certain
wearing-comfort appeal. Such a layer, when employed, is distributed
preferably in the form of an enclosure bag around core structure
16. This bag might typically take the form of a polyester fabric,
such as fabric known as Orthowick made by Velcro Laminates, Inc.,
54835 C.R. 19, Bristol, Ind. 46507.
[0028] The right side of pad 12a in FIG. 3 is referred to herein as
the body-facing side, and the left side of the pad in this figure
is referred to as the load-facing side. Each of the two sublayers
(16a, 16b) which make up core structure 16 is formed, importantly,
of a suitable acceleration-rate(strain-rate)-sensitive material,
such as a viscoelastic urethane
compression-deformation-and-slow-return material, which possesses,
in technical terms known to those skilled in art,
acceleration-rate(strain-rate)-sensitivity.
[0029] With regard to acceleration-rate(strain-rate)-sensitivity,
the materials in sublayers 16a, 16b respond to compressive
accelerations each with a compression-deformation resistance
behavior 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
materials, if that pressure application is done at a very low
acceleration rate, the materials respond very readily and fairly
instantaneously with a yielding deformation response. However, if
such a pressure is applied rapidly, i.e., with a rapid (large)
acceleration rate, the materials tend to act very much like solids,
and they do not respond rapidly with a yielding deformation action.
Generally speaking, the higher the rate of acceleration associated
with an applied compressing force, the more like a solid material
do sublayers 16a, 16b behave. An important consequence of this
acceleration-response characteristic is that the structure of the
invention offers, in relation to prior art structures, a superior
shock-cushioning action. It thus offers a significant improvement
in injury avoidance. A contributing factor also in this regard is
that the materials in sublayers 16a, 16b, after undergoing a
compressive deformation, return relatively slowly toward their
pre-deformation configurations.
[0030] The preferred two-sublayer make-up for core structure 16 is
further characterized by the fact that the rate-sensitive,
viscoelastic material in sublayer 16a has a lower durometer and
Indentation Load Deflection (ILD) response number than does the
material in sublayer 16b. Specifically, and in the construction now
being described, sublayer 16a has a durometer with an ILD number
(or rating) preferably no less than substantially 15-ILD, and
preferably further in the ILD number range of about 15 to about 28.
Sublayer 16b has a durometer with an ILD rating preferably in the
range of about 42 to about 55. Sublayer 16a herein is made of a
viscoelastic material designated as Confor CF-40, made by a company
called EAR Specialty Composites in Indianapolis, Ind. Sublayer 16b
is made of a viscoelastic material designated as Confor CF-45, also
made by this same company.
[0031] 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 T.sub.1), is preferably about 7/8-inches.
Sublayer 16a has a thickness pictured in FIG. 3 at T.sub.2
(measured in the same fashion) preferably of about 3/8-inches, and
sublayer 16b, a thickness pictured in FIG. 3 at T.sub.3 preferably
of about 1/2-inches. Different thickness dimensions may, of course,
be chosen for various purposes, including for "sizing" purposes, to
aid in achieving a proper and comfortable helmet fit.
[0032] Within the context of a two-sublayer make-up for core
structure 16, and with respect to an overall core structure
thickness which is greater than about 1/2-inches, it is preferable
that the thickness of sublayer 16a be maintained at no less than
about 3/8-inches. Where the overall thickness of core structure 16
is reduced to about 1/2-inches or less, it is preferable here that
this core structure be made of but a single layer of "lower
durometer type" viscoelastic material, but preferably with and ILD
number which is no less than about 15-ILD.
[0033] Under all circumstances, it is preferable, where a
multi-sublayer structure is employed for core structure 16, that
the component thereof which is toward the body-facing side of the
whole assembly have the lowest (in the case of more than two
layers) durometer ILD number associated with it.
[0034] Another consideration regarding the structure of core
structure 16 is that, preferably, it have a quite uniform thickness
throughout. Uniformity of thickness plays an important role in
maximizing the capability of this core structure to conform as
precisely as possible with, in the case of a helmet, the topography
of the wearer's head. My practice has been to create such a core
structure with an overall thickness which lies within a tolerance
range of about .+-.0.002-inches. This is the thickness tolerance
which characterizes the core structure pictured in helmet 10.
[0035] Within the three-dimensional body of each of the two
viscoelastic sublayers, there is no other structure present, save
ambient and entrained gas. Accordingly, each such body responds to
shock loads substantially uniformly, and omnidirectionally,
throughout its entirety.
[0036] Pad 12a is suitably and preferably releasably anchored to
the inside of helmet shell 10a through a two-component conventional
hook-and-pile structure 24 typically sold under the name Velcro--a
readily commercially available product made by Velcro USA, Inc.,
406 Brown Avenue, Manchester, N.H. 03108-4806. One component of
this hook-and-pile structure is suitably attached either directly
to core structure 16, or to any outside-layer covering structure
employed with this core structure, and is located on what was
referred to earlier as the load-facing side of pad 12a. The other
component of the hook-and-pile structure is suitably joined to the
inside surface (at the appropriate location) of helmet shell
10a.
[0037] FIG. 4 in the drawings illustrates a modified form of a
load-cushioning pad 12a made in accordance with the invention. This
pad differs from the pad as shown in FIG. 3 by the fact that core
structure 16 here includes but a single,
acceleration-rate(strain-rate)-sensitive, viscoelastic component,
or instrumentality, shown at 16c. Component 16c has a thickness,
indicated at T.sub.4 in FIG. 4, of about 1/2-inches, and is formed
generally of the same kind of viscoelastic material described
earlier as having a durometer rating with an ILD number in the
range of about 15 to about 28. Thus, component 16c herein is
preferably made of the EAR Specialty Composites material designated
as Confor CF-40.
[0038] 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
improvements over related prior art structures.
[0039] If and when a shock load is transmitted through the helmet
shell to the head of the wearer, it emerges on the inside of the
shell as a blunt-trauma-type event which is delivered to the
inside-installed load-cushioning structure, 16. The rate-sensitive
nature of structure 16 causes that structure to respond with the
very effective behavior described earlier herein, namely, to act in
an acceleration-resistant and anti-spring-back fashion that causes
such an event to be further distributed over a very broad expanse,
and to be managed without there being any negative and dangerous
rebound repercussions.
[0040] Very specifically, within a helmet shell, the
load-cushioning structure of the invention defines what is referred
to herein as a load-transmission path between this shell and the
head of a wearer. Such a path can be visualized by looking, for
example, at FIGS. 3 and 4 in the drawings with the idea that a
horizontal line passing generally vertically centrally through
these fragmentary views essentially highlights such a path where it
extends between the inside of the pictured helmet shell and the
inner side of structure 16. Within this path, a shock load
delivered to the outside of the helmet shell causes a compression
deformation first response, and a subsequent slow return, or
second, response, to occur in structure 16. This response behavior
of structure 16 solely determines how the head of a wearer
experiences the triggering shock load. In other words, there is no
other compression-and-return material involved in this
load-transmission path, and especially, no material in this path
which can introduce any form of a springy, spring-back, rebound
(resiliency) response. This behavior is strikingly contrastable
with prior art behavior which seems always to focus upon achieving
intentionally some form of such a springy reaction response.
[0041] This unique behavior of the present invention causes it to
offer superior ballistic response capabilities in relation to
preventing the likelihood of a serious head injury. The operational
features of load-cushioning structure 16--compression
deformation-and-slow-return viscoelasticity, non-springy
anti-rebound, and acceleration-rate(strain-r-
ate)-sensitivity--contribute significantly to the invention's
superior behavior.
[0042] The invention, as proposed, may take the form, for example,
as a shock-absorbing structure per se intended for use inside the
shell of a helmet. It may also take the form of a combination of a
shock-absorbing structure and a rigid helmet shell.
[0043] While the invention has been disclosed in particular
settings, and in particular forms herein, the specific embodiments
disclosed, illustrated and described herein are not to be
considered in a limiting sense. Numerous variations, some of which
have been discussed, are possible. Applicants regard the subject
matter of their invention to include all novel and non-obvious
combinations and subcombinations of the various elements, features,
functions and/or properties disclosed herein.
* * * * *