Note: Descriptions are shown in the official language in which they were submitted.
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Title: PROJECTILE RESISTANT STRUCTURE
This application claims the benefit of United States Provisional Application
Serial No.
60/054, 379, entitled "Projectile Resistant Structure", filed July 31, 1997.
TECHNICAL FIELD
The invention relates to protective shield structures; more particularly, it
relates to soft
puncture-resistant armor made of laminated woven light-weight fiber materials
for stmctures,
including highly adaptable projectile-resistant shield panels, and for vests
and other protecti~.-e
garments for persons and other living things.
BACKGROUND OF THE INVENTION
It is estimated that worldwide an average of roughly 1000 people have been
killed by
bullets, bomb fragments, knives, arrows, and other puncture-causing objects or
projectiles every
single day during the 20th century. Wars have brought terrible casualties,
often more civilian
than military; law enforcement officers live in perpetual jeopardy; crime
takes fearful toll among
the peaceful; and political terrorism has provided new depths of horror.
Of these tens of millions dead, many millions could have been saved, with
their unique:..
diverse, and sometimes brilliant talents, their love, and their abilities,
through the use os
puncture- or projectile-resistant protective armor, either in the form of
vests or other garments,
or eternally as armor for walls, doors, vehicles, and the like.
And the human cost is not ail. Many law enforcement or humanitarian missions
have
been defeated through the destruction of critical or sensitive equipment by
bullets, tra~ments c:,r
other projectiles; and many millions of dollars in material damage have been
suffered. And as
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with the waste of human life, much of this material damage could have been
averted through the
use of puncture- or impact-resistant armor or other protective materials.
Protective materials are not entirely unknown. For example, soft armor
material is
known which is made from a plurality of fabric layers of light-weight, high
strength fibers,
particularly aramid fibers, such as those sold under the trademark Kevlar, and
polyethelene f bers,
such as those sold under the trademark SPECTRA. A typical soft armor material
made from
such fabric material is typically tailored in the form of a jacket or vest and
is used to protect
individuals against handgun, shotgun, club and knife assaults. Likewise,
attempts at providing
protection for persons within structures have been made. For example, Babbaza
U.S. Pat. No.
i 0 5, l 64,536 discloses an armor resistant seat primarily utilizing ceramic-
matrix composites as the
ballistic resistant materials; and Dunbar U.S. Pat. No. 5,200,256 shows a
variety of armored
lirvngs, each of which employ rigid or relatively inflexible shield layers and
in each of which the
shield layers are strongly bonded to one another, for use with vehicles of one
sort or another.
Even some flexible armors have been suggested. McArdle, U.S. Pat. No.
3,294,038, entitled
Fragment Suppression Configuration, provides a protective system which
includes a blanket
portion composed of at least two layers of ballistic nylon felt interposed
with an inner lamination
or ply and enclosed with a ballistic nylon cloth envelope. A prime protective
surface or layer
composed of ceramic or tile assembly incorporates a plurality of individual
~~ightly spaced tiles
each mounted with its faceside boned to an overlapping double layer glass
cloth and its rearside
covered with a separate metal backplate which is bonded with the metal
backplate side and
overlapping portions of the glass cloth against the faceside of the blanket.
An armored
skin-diving. suit is the subject of U.S. Pat. No. 4,356,569 issued to
Sullivan; the Sullivan device
provides a flexible garment portion with a plurality of armor elements spaced
at intervals thereon.
Protective vests constructed of material having projectile stopping
capabilities are also known.
An example is shown in U.S. Pat. No. 4,483,020 to Dunn, entitled Projectile
Proof Vest. 7'he
Dunn device includes a network of rigid inner shock resistant plates lying
under a layer of
ballistic material, in order to minimize the force imparted by a slowing
projectile upon the wearer
of the vest. An example of metal armor is seen in U.S. Pat. No. 4,534,266
entitled Composite
Armor Plating to Huet. The Huet device provides a composite metal armor
comprising ceramic
inserts arranged in a regular manner within a metal casing.
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Yet there is a continued need for increased stopping power and increased
efficiency in
projectile-resistant structures. Each of -the devices described above relies
upon the use of
bonded, typically resin-saturated shield or fabric layers, and many of them
incorporate heavy
metal, ceramic, or metal-mesh reinforcing plates and layers, none of which are
flexible or
comfortable, and some of which can cause substantial injury of their own under
heavy impact;
inflexibility leads to wearer discomfort in armored apparels and to an
inability to adapt
prefabricated armor panels in a wide variety of structural uses. None of the
devices will float i;~
water, and few of them are adaptable enough to perform alternatively as vests,
personal flotation
devices, floating structures, armored blankets and portable armored shields,
and integral armored
construction for the protection of lives, equipment, and property. Nor can
these prior devices
prevent exit of a projectile at the edges of the protective panels. Moreover,
each of the devices
requires a great many layers of fabric to be effective in stopping a bullet,
particularly if the bullci:
is spinning (as for example a result of being fired from a rifled barrel): the
aramid fabric layers
of these structures are all bonded together, and structures in which the
layers of aramid fiber
I S fabric are bonded together tend to permit a spinning bullet to pass
through without capturing
being captured, and hence are only successful as bullet proof structures by
virtue of the use of
many more layers than is needed in the present invention.
There is a need for a system which solves these difficulties and provides a
strong,
lightweight, projectile-resistant, flexible, optionally floating structure
adaptable to a wide variety
of structural and personal applications, including vests, portable shields.
personal flotation
devices, floating structures, and the protection of otherwise unprotected
persons, property, and
equipment.
DISCLOSURE OF INVENTION
Accordingly, it is an object of the invention to provide a strong,
lightweight, projec.tiie-
resistant, flexible, optionally floating structure adaptable to a wide variety
of structural and
personal applications, including vests, portable shields, personal flotation
devices, fioating
structures, and the protection of otherwise unprotected persons, property, and
equipment.
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It is a further object of the invention to provide a projectile-resistant
structure capable
of stopping spinning projectiles, such as spin-stabilized or otherwise
spinning bullets or
fragments.
It is a further object of the invention to provide a projectile-resistant
structure capable
of stopping high energy projectiles with fewer shield layers than previously-
known projectile-
resistant devices.
It is a further object of the invention to provide a projectile-resistant
structure which
reduces or eliminates the tendency of projectiles to "run" or travel" along
the surface of the
structure toward an edge of the structure following impact.
It is a further object of the invention to provide any or all of the foregoing
structures in
light-weight form.
It is a further object of the invention to provide any or all of the foregoing
structures in
flexible form.
It is a further object of the invention to provide any or all of the foregoing
structures in
a comfortable form when incorporated in garments or other personal wear.
It is a further object of the invention to provide any or all of the foregoing
structures in
a form which floats in water or other fluids.
It is a further object of the invention to provide any or all of the foregoing
advantages
in a personal flotation device.
It is a further object of the invention to provide any or all of the foregoing
advantages
in a personal flotation device having selectable or adjustable flotation and
protective
characteristics.
It is a further object of the invention to provide any or all of the foregoing
structures in
a form in which glues and resins are not required, and in which shield layers
are not impregnated
or saturated with resins and are not bonded to each other.
It is a further object of the invention to provide any or all of the foregoing
structures in
a form which provides improved insulation potential for human users.
It is a further object of the invention to provide any or all of the foregoing
advantages
in a projectile-resistant shield panel adaptable for use with a wide variety
of structures, vehicles,
and the like.
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It is a further object of the invention to provide any or all of the foregoing
advantaf,es
in a projectile-resistant pontoon adapted for use with marine vehicles and
structures.
It is a further object of the invention to provide any or all of the foregoing
advantages
in a portable projectile-resistant shield.
It is a further object of the invention to provide any or all of the foregoing
advantages
in a projectile-resistant briefcase.
It is yet another object of the invention to meet any or all of the needs
summarized above.
These and such other objects of the invention as will become evident from the
disclosur;;
below are met by the invention disclosed herein.
The invention addresses these concerns and provides such a system. The
invention
provides soft armor protection for both structures and living beings through
the use of multiple
layers of unbonded protective shield layers comprised of, for example, aramid
fiber fabr ics,
optionally backed by a relatively soft, impact-absorbent foam layer. The soft
foam layer acts to
dissipate and spread the impact of a projectile while the unbonded fabric
layers capture the
projectile, particularly when the projectile is spinning, as in the case of a
bullet fired from a rifled
barrel.
The composite projectile- or puncture-resistant panel of the invention is
generally formed
by wrapping one or more layers of relatively soft, energy-absorbent dense,
lightweight foam with
layers of protective, generally flexible shield material such as aramid fiber
fabrics. When shield
layers comprised of anisotropic materials or fabrics are used -- as for
example aramid fiber
fabrics -- preferred embodiments are formed by alternating the bias of
successive wrap layers.
This alternation or offsetting of bias orientations in various layers of the
shield fabric has beer
found, among other things, to discourage or prevent egress of a bullet through
unwrapped edges
of the panel, or partial capture and "travel" of projectiles along the face of
various plies of shic~lr!
material. Wrapping the shield layers around the core, or using the core in
conjunction with
unwrapped layers on either one or both sides of the core, enhances the
performance of the
composite panel by putting the core in position to spread the impact of the
projectile over a nnic',~
larger area than the projectile would otherwise typically affect, thus
reducing or entirely
preventing blunt trauma injury and minimizing the number of aramid fabric
layers in the
construction of the panel. For example, in the case of an embodiment employing
a wrapped
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core, a particularly penetrating projectile might breach an entire outer set
of shield layers, or an
outer panel of such layers, pass into or through the soft foam core, and be
captured by the inner
set of shield wraps or by a separate inner panel. The composite shield-
laminate and core panel
of the invention is adaptable to a myriad of uses including vests, water
survival suits, personal
flotation devices; portable shields such as projectile-resistant panels and
attache cases; vehicle
door, wall and roof panels; and bulletproof floats and pontoons for inflatable
watercraft and float
planes and the like.
One aspect of the invention provides a projectile- or puncture-resistant
structure, or
panel, comprising a plurality of flexible shield layers or laminae. The
individual layers are
stacked to form a panel, but are not bonded to each other, though they may and
in many
preferred embodiments are attached at one or more edges or at their
peripheries. It has
heretofore been the virtually universal practice, in fabricating laminated
armor panels, structures
or personal protective devices, to fully bond each of the individual shield
layers, or "wraps," of
the panels or structures to each other by saturating the layers with adhesives
prior to laying them
up into panels and allowing the adhesives to set. It has been found as one
aspect of the
invention, however, that stacking or laying up the layers, or laminae, into
panels without bonding
the individual layers or laminae together enhances the overall puncture-
resistant or projectile-
stopping properties of the panel, particularly with regard to spinning
projectiles. This is because
when a first of the layers in such a panel is struck by the spinning
projectile, the fibers of the layer
(sometimes broken by the impact) snag or grab the projectile, typically
through friction or by
actual snagging of irregularities in the surface of the projectile (as for
example rifling marks on
a bullet fired from a rifled barrel). When individual layers of the panel are
not bonded to each
other, the layers are free to move and more firmly grasp and slow the
projectile until it stops,
particularly if one or more of the outer layers are actually pierced and the
projectile is engaged
by inner layers, each of which acts in the same manner to slow and stop the
projectile. Ln
addition, unpierced layers of shield material act in more conventional manner
to stop tYce
projectile through tensile action along the fabric fibers. It has been shown
through tests that the
stopping power of panels according to this aspect of the invention is superior
to conventional
bonded pmels, and that penetration of panels according to the invention,
particularly by spinning
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projectiles, is less likely than their conventional counterparts under similar
conditions and
utilizing similar numbers and types of shield layers.
Generally preferred embodiments of the protective, projectile- or puncture-
resistant
shield aspect of the invention are comprised of anisotropic puncture-resistant
materials. As is
well known, anisotropic materials are those which exhibit different
characteristics, as for example
stiffness or ultimate tensile or shear strength, in various directions. Such
materials are said to
posses structural "biases" in those directions. For example, many composite
materials are
composed of substantially-aligned fibers of great strength and high tensile
modulus. Such
materials are extremely strong and extremely stiff along the axis of their
aligned fibers, and
exhibit substantially lower strength and stiffness in other directions. The
axes of greatest
strength and stiffness in anisotropic materials are typically referred to as
the "principal axes" of
the material. Many aramid fiber fabrics exhibit such anisotropic
characteristics, or "bias," due
chiefly to the manner in which they are woven; the "warp and weft" of their
weave provides
distinct properties in various directions. In embodiments of the invention
comprising shield
layers made of such materials, it has been found that stacking layers of the
material so that the
principal axes or the "bias" directions of two or more of the various layers
are rotationally offset
from each other offers significant advantages for slowing and stopping
projectiles or other
puncturing or piercing objects, particularly when the projectiles or objects
are spinning. Fur
example, it has been observed that spinning projectiles such as bullets fired
from rifled barrels
have a tendency, when striking panels comprised of layers of anisotropic
materials, to spin along
the fabric either with or across the weave, and thus to travel or "run" along
or parallel to the
surface of the various shield layers toward the edge of the panels, sometimes
exiting the panels
at an edge. It has been found that when bullets strike panels composed of the
same materials
with the principal axes of the various layers rotationally offset from each
other, this tendency <;an
be reduced or altogether eliminated. In particular, it has been found
advantageous in preventing
this "traveling" of such projectiles to offset the principal axes of the
various layers by angles of
at least approximately 30 degrees, with best results being observed when
alternating layers are
offset at approximately right angles, or 90 degrees. For example, in a twenty-
ply (or ten-wrap,
generally there are two plies per wrap) panel it has been found to be
particularly advantageous
to align the principal axes, or biases, of the first, third, fifth, seventh,
and ninth wraps, and to ~a_v
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the second, fourth, sixth, eight, and tenth wraps with their axes, or biases,
aligned at right angles
to the others. Panels constructed with such orientations of their anisotropic
layers have exhibited
great strength and penetration resistance, and a marked tendency to reduce or
eliminate travelling
or running of projectiles after impact.
A further aspect of the invention is the provision within the shield panel of
a substantially
soft, impact-dissipating core. The core may be disposed next to or among any
of the individual
shield layers. In preferred embodiments the core is disposed between shield
layers, either by
stacking up individual layers or by wrapping continuous shield material around
the core. Ur;e
of the functions of the core is to absorb the impact of a projectile or other
object striking the
individual shield layers and to both dissipate and spread the impact through
the shield layers and
ultimately to the structure or person supporting the shield, with a minimum of
blunt-trauma type
injury resulting. In preferred embodiments of the invention the core is made
from relatively soft,
flexible, light-weight material such as lightweight dense foams derived from
various materials,
including plastics. Light-weight, water-resistant fibers being well known and
generally available,
the core may be used to provide yet another advantage: when fabricated of
water-resistant
materials (i.e. those which do not readily absorb water) less dense than water
(either fresh or salt
water), the core can be used to both protect and support persons or objects in
the water or other
fluids, as for example in the fabrication of personal flotation devices or
pontoons, floats, or the
like.
2.0 Thus another aspect of the invention is a personal flotation device
designed for wear by
human beings, and in particular human beings possessing both a torso and a
head. Preferred
embodiments of such flotation devices comprise one or more protective panels
of the typ;~
described above, with pluralities of flexible shield layers stacked with or
wrapped about a
substantially soft energy absorbent core, typically water-resistant foam of
lesser density than
water. The cores of such devices need not be sandwiched between shield layers,
but may lie next
to a set of such layers, preferably on the side of the panel closest the
wearer of the device. The
panels of such devices are fabricated to cover and fit the torso of the wearer
in the manner of a
vest, and thus to provide coverage to most or a substantial portion of the
wearer's torso. Tl~us
flotation devices according to this aspect of the invention may serve the dual
purpose;. eon
protecting the wearer from projectiles or other potentially dangerous or
penetrating objets, aad
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of keeping the wearer afloat, either in water or (if constructed of suitable
materials) in other
liquids. Such devices may also be adapted to protect the wearer from heat or
cold, by the
selection of suitably-insulating core and shield layer materials.
It has been found that great advantage may be gained by providing personal
flotation
devices or other protective garments according to the invention with auxiliary
panels adapted for
selective attachment to one or more various locations on the main flotation
panel(s). Preferred
embodiments of these auxiliary panels comprise a plurality of flexible ~'iield
layers and a
substantially soft energy absorbent core, in the manner of other panels
according to the invention,
the core being disposed either next to the shield layers or between any two of
them in a manner
generally similar to the primary panel(s), and may be configured in any of the
general forr.~s
described herein, including by providing cores composed of water-resistant
materials less dense
than water, so that they may aid in supporting a wearer in the water. By
allowing selective
and/or adjustable attachment of such auxiliary panels to the main panels) or
to such panels'
earner both the flotational and puncture-resistant / protective
characteristics of the device may
be tailored with relatively great precision to accomplish a broad range of
purposes. Selective
positioning and adjustment of auxiliary panels is accomplished in a number of
ways, as by means
of snaps, buttons, zippers, hook and loop fasteners, or other conventional
means.
It has further been found advantageous to adapt personal floatation devices
according
to the invention such that a portion of the panel is disposed behind the
wearer's head, so as to
provide additional flotational support and impact protection to the wearer
while the device is
worn. Typically this may be accomplished by extending the rear portion of the
main panel
upward behind the shoulders and neck of the wearer until it extends all or
part of the way behind
the wearer's head. Preferred embodiments of this aspect of the invention
further take advantage.
of such configurations by adding a handle to the neck or head portion of the
vest to facilitate
carriage and handling of the flotation device.
Panels according to the invention may be put to a wide variety of protective
uses. For
example, such panels may be employed with or without cores as moveable, easily
installable
protective panels in cars (particularly in car doors, roof liners, carpets,
and the like), aircraft
(including helicopters), boats, and other vehicles; in podiums and other
structures; as "bomb
blankets", or free panels used to cover potentially explosive devices or to
provide moveab!~;
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cover, or as bulkhead shields for aircraft cargo holds and the like; or as
integral or removable
seat cushions. They may be mounted permanently or impermanently, by means of
any suitable
conventional fasteners, such as screws, rivets, snaps, etc., or hook-and-loop
fasteners; a.nd they
may be encased as integral pants of a structure or hung bare on walls,
bulkheads, or partitions.
Groups of individual panels may even be used by besieged or otherwise
threatened individuals
to construct small, temporary protective enclosures in times of need. The
details of th;:,
fabrication of shield panels, roof liners, seat covers, bomb blankets, and the
like according to the
invention, beyond those critical details disclosed in this specification, will
be well known in the
art and well within the ability of the skilled designer of protective devices
once he or she has been
armed with the disclosure of the invention.
A specific and particularly advantageous use to which core-employing panels
accordintY
to the invention may be but is the construction of impact-, puncture, or
projectile resistant
pontoons and floats for boats, planes, and the like. Preferred embodiments of
this aspect of the
invention comprise a core having an outer surface, a plurality of shield
layers, and a coveriric;.
The core is typically water-resistant and less dense than water, as described
above. The pturality
of shield layers being wrapped about the outer surface of the core, optionally
with the offset bias
or principal axis of~'set discussed above; the layers may be wrapped many
thicknesses deep. 'fhz
covering is typically disposed about the shield outer layer, for structural
support of the pontoon
and protection of the pontoon from exposure to weather and the environment in
which it is used.
For example, different coverings may be required for various operations in
mining slag pools than
fresh water; the selection of proper covering materials will involve many
factors. such as
exposure to ultraviolet rays, sunlight, heat, water, minor impacts, or other
enmronmental factors.
The evaluation of such factors and the selection of an appropriate covering
material is well within
the ken of the ordinary designer of such pontoons, once he or she has been
armed with the
disclosure of the invention. As generally described above, the shield layers
in such a protective
structure are preferably not bonded to each other, so that when a first of
such layers is struck b~:
a spinning projectile the layer acts without significant structural support
from any other layer
in countering the rotation of the projectile. Moreover, they are typically
comprised o'
acusotropic puncture-resistant materials and are wrapped so that the principal
axes of at least two
of the layers are rotationally offset from each other, preferably by angles
ranging fro~a
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approximately 30 degrees to substantially normal or perpendicular (90
degrees). Cores
according to this aspect of the invention may be provided with auxiliary
reinforcement, either by
means of the shield layers or the covering, or by means of internal
reinforcement, such as
integrally provided re-bar or structural framing.
It is anticipated that preferred embodiments of any of the various panel
aspects of the
invention discussed will be used in conjunction with panel covers. Such covers
are generally
intended for use in deploying and protecting shield panels. For example, in a
personal flotation
device according to the invention, a cover may advantageously be employed to
help fit the
flotation device to its wearer, and to hold it in place, and to support
straps, attachments, pockets,
insulating layers, etc., as well as to protect the shield panels and core from
exposure to the
elements and from damage. Likewise, a cover for a moveable shield panel may be
employed to
mount the panel, to hang it on a wall, or for identification, visibility, or
marketing purposes as
well as protection of the panel itself. The selection of appropriate materials
for such structures,
will, again, be well within the ability of one skilled in the relevant art.
Another aspect of the invention involves a specific application of the shield
panel aspect
of the invention in providing a portable projectile-resistant shield.
Preferred embodiments of this
aspect of the invention comprise one or more protective panels, according to
the foregoing, and
a briefcase. the briefcase being sut~icient in size to cover a substantial
portion of a typical human
torso, so that it may be held before one's body and used to shield the user,
and particularly the
user's vital organ cavity, ti-om projectiles or unwanted impacts. Generally
the method of using
tl-us shield aspect of the invention is to dispose the shield panel inside the
briefcase somewhere,
as along one of the larger sides or in a liner of the briefcase, and to hold
it up, when threat~n~d,
before the body so as to interpose it between the user and any unwanted
potentially impacting
objects. One way of stating this is to say that the briefcase shield is
typically izeld out before its
user so that the briefcase is generally perpendicular or normal to a ray
emanating from the center
of the user's torso, which generally has the effect of placing the shield
layer substantially
perpendicular to the line of travel of potentially impacting objects, so that
the shield rr~ay most
effectively stop, slow, or deflect them. Preferred embodiments of this aspect
of the invention
employ briefcases at least 13 "x 17" in major dimension (this having been
found to be sufficient
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to cover most human vital organ cavities), with shield panels suitably sized
to fit, depending .gin
the application to which the shield is to be put.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a preferred embodiment of the invention
being struck
by a projectile.
Figure 2 is a schematic view of a preferred embodiment of a plurality of
anisotropic shield
layers according to the invention.
Figures 3a and 3b are schematic cutaway views of a preferred embodiment of a
projectile
resistant structure aspect of the invention being struck by a projectile.
Figure 4 is a schematic view of a preferred embodiment of the personal
flotation device
aspect of the invention.
Figure 5 is a perspective view of a preferred embodiment of the personal
flotation device
aspect of the invention.
Fi~,rure 6 is a perspective view of a preferred embodiment of the personal
flotation devic,:
aspect of the invention.
Figure 7a is a perspective view of a preferred briefcase embodiment of the
portable
projectile resistant shield aspect of the invention. Figure 7b is a cutaway
view of a preferred
briefcase embodiment of the projectile resistant shield of the invention.
Figures 7c, 7d., and 7e
are schematic views showing the sizing and use of a briefcase embodiment of
the projecti~w
resistant shield of the invention.
Figure 8 is a perspective view of a preferred pontoon embodiment of the
projectii;
resistant structure aspect of the invention.
Figures 9a and 9b are perspective views of marine applications of preferred
embodiments
of shield aspects of the invention.
Figure 10 is a perspective view of several preferred embodiments of the
projectiir~
resistant shield aspect of the invention incorporated in an automobile.
Figure 11 is a perspective view of several preferred embodiments of the
projectile
resistant shield aspect of the invention incorporated in an aircraft.
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Figure 12 is a perspective view of a preferred embodiment of the projectile
resistant
shield panel aspect of the invention. -
BEST MODE OF CARRYING OUT THE INVENTION
When used in this specification, the term "projectile resistant" means having
an ability or
tendency to resist puncturing, impact, and other damage caused by ballistic
and thrusted or
otherwise propelled objects, such as for example bullets, knives, arrows,
shrapnel, and fragment.
For purposes of the specification the term is interchangeable with the terms
"impact resistant"
and "puncture resistant."
To say that two or more shield layers are "bonded" to each other means, within
the
meaning of this specification, that the layers are field-glued, resined,
fizsed, epoxied, cemented,
adhered, or otherwise broadly, globally or generally fixed, stitched, or sewn,
or otherwise
mechanically fastened to one another, or adapted so as allow shear load
transfer from one
bonded part to another, over a significant portion of their surfaces. Being
glued, sewn, hemmed,
seamed, or otherwise fixed or secured at one or more edges or at a periphery
for the purpose of
securing or completing a group of layers as a panel, a segment of a panel,
garment or like device
is not "bonded" in this sense. For example, in a personal floatation device
according to the
invention the edges of individual shield panels are typically sewn together,
in order to allow the
panels to retain their proper shape, but the panel layers are not, for
purposes of this disclosure,
considered bonded because of it.
Turning now to the drawings, the invention will be described in a preferred
embodiment
by reference to the numerals of the drawing figures wherein like numbers
indicate like parts.
Figure 1 is a perspective view of a preferred embodiment of the invention
being struck
by a projectile. Projectile 1, depicted as a bullet, has been fired in the
direction of arrow 40 and
is spinning in the sense shown by arrow 41. Shield layers 20 are stacked
against each other but
are not bonded together, with the result that when projectile 1 strikes first
or outermost shi~l~_i
layer 2 and (in the case depicted, but of necessity) breaks several of fibers
21 of first shield lay;~~.r
2, both broken and unbroken fibers grab or snag the projectile such that
continued spinning of
the projectile places the fibers in tension, as indicated by arrows 42,
causing them to resist thL
spinning. Because shield layers 20 are not bonded to each other, they are
relatively free tees
13
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WO 99/06785 PCT/US98/15743
deflect, or even bunch together in response to the tension induced in the
individual fibers. adding
the work of the layer-displacement to work done by the shield layer in
countering the rotation
of the projectile. To the extent that the projectile breaches the first layer
and proceeds to contact
second layer 30, the process is repeated, with several of fibers 21 in the
second layer snagging
the projectile, placing the fibers in tension and causing the layer to bunc.:.
>vloreover, any
additional, unbreached layers act in more conventional manner to resist
penetration of the
projectile, the fibers of such panels being placed in tension by the attempted
passage of projectile
1. 'The action of slowing or stopping the spinning of the projectile in this
manner contributes to
the greater efTrciency of the invention than previous protective shields,
permitting projectiles to
be stopped with fewer layers than previously possible due to bonding of the
various shield layers
to each other.
Figure 2 is a schematic view of a preferred embodiment of a plurality of
anisotropic shield
layers according to the invention. The four anisotropic puncture-resistant
shield layers 45 any?
46 are comprised of fibers 21 bound together into sheets or layers 20 by means
of binders 22.
1 ~ Both because fibers 21 generally have greater tensile stiffness and
strength than binders 22 and
because of the geometry of the construction of the layers 20, layers 20
exhibit much greater
strength and stiffness in a direction parallel to their respective fibers 21.
That is, the two layers
45 exhibit greater stiffness and strength in the direction of arrows 44 than
in the direction ef
arrows 43, while the two layers 46 exhibit greater stiffness and strength in
the direction of arrows
43 than in the direction of arrows 42. Thus layers 46 may be said to possess
principal axes, or
to be structurally biased, in the direction of arrows 43, while layers 45 may
be said to posses
principal axes, or to be structurally biased, in the direction of arrows 44.
In the Figure layers 4~
and 46 have been stacked alternately so that angle 47 between the principal
axes (or the "bias"1
of alternate layers is approximately 90 degrees, and alternate layers are laid
down with
substantially normal or perpendicular biases. It has been found that stacking
the layers with
substantial offset between the bias or principal axes helps greatly in
preventing the "running" or
"traveling" of bullets along the surface of the shield layers. Any substantial
offset will suffice,
from approximately 30 degrees and up, with excellent advantage and generally
superior "nrn"
stopping performance occurring at approximately 90 degrees offset.
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WO 99/06785 PCT/US98/15743
Figures 3a and 3b are schematic cutaway views of a preferred embodiment of a
projectile
resistant structure aspect of the invention being struck by a projectile.
Projectile-resistant
structure 30 is comprised of laminated shield 23 and substantially soft,
impact-dissipating cere
3. Core 3 is enclosed in wrapped laminated shield 23 comprised of a plurality
of individual shield
layers 20, and thus disposed between two portions of the same innermost
continuous shield layer.
In many embodiments core 3 is not fully wrapped in laminated shield 23, but
simply disposed
next to an outer shield layer. In the Figure projectile 1 is shown prior to
and following impact
with outer shield layer 2 (on impact the projectile has flattened and its
shape has been deformed).
Laminated shield 23 has absorbed much of the impact of the projectile,
spreading the resultant
toad through its individual layers 20 by means of tension, as shown by arrows
48, and into cure
3, which has absorbed much of the impact and spread or dissipated the impact
(as shown by
arrows 49) through the core and into the supporting structure or the wearer's
body, so that the
blunt trauma experienced by or induced in any structure (or body) supporting
projectile-resistant
structure 10 by projectile 1 will be spread over as wide an area as possible
and minimized.
Preferred materials for fabrication of the shield layers of the invention
include polymeric
aromatic amide (polyaramid) fiber-based fabrics (such as that marketed under
the tradename
KEVLAR) and extended-chain polyethelene (ECPE) fiber fabrics (such as that
marketed under
the tradename SPECTRA). For substantially soft, impact-dissipating cores, and
in particular for
those cores intended for use in personal flotation devices according to the
invention, relatively
soft, water resistant, flexible, light-weight but dense material such as foams
d:~ived from various
materials, including plastics are used. Preferred materials for use in
fabricating cores according
to the invention include closed-cell cross-linked polyethelene, or
polyethelene / EVA foams with
fine cell molecular structure; in particular, the foams marketed under the
designation Dupont
MC 1900 Microcell Poiyethelene EVA foam or the tradename ENSOLITE. Wrapped-
core shield
panels according to the invention and capable of stopping most handgun-fired
bullets have been
fabricated using as few as 10 wraps of Poly (P-Phenylene Terephthalamide)
Aramid I29, Lincoln
Fabrics Ltd. Style #33b3 KEVLAR (a nominal 28x28 fiber weave) wrapped atop one-
inch
thicknesses of MC 1900; preferred embodiments of the invention have used
between 3 and 25
shield layers of such materials on a one-inch core. However, the penetration-
resist~rt
characteristics required of a given shield panel will vary, depending upon the
use to which ahe
*rB
CA 02298670 2000-O1-31
WO 99/06785 PCT/US98/15'743
panel is to be put and the types of penetration it is intended to prevent. A
wide variety of
materials will be well suited to various environments and threats. Once the
inventor has bee.o
armed with the disclosure of the invention, an undue amount of experimentation
will not k;L.
required before a suitable combination of numbers and types of shield layers
and cores will bP
found; at most the making of a few prototypes according to the invention will
be required, wioh
testing. Covers for many embodiments of the shield panel and other aspects of
the invention may
be made from a wide variety of materials, including canvas, cotton, nylon,
robber, neoprene, <Fr»:1
various polymers and synthetic materials. The selection of proper cover
materials will dep~sr:d
upon the use to which a particular application is to be put, and the
environment in which it is to
be used, and will lie well within the ability of the ordinarily-skilled
desige. ~r armed with the
disclosure of the invention.
Fi~,n,rre 4 is a schematic view of a preferred embodiment of the personal
flotation device
aspect of the invention. The device is shaped to fit the torso and protect the
rear of the head of
a human wearer and to allow the arms of the user pass through indentations 55
in the periphery
I5 of the device, so that the wearer may be simultaneously both protected and
free to move willus~:s
undue restraint. Covering 50 covers both front panel 51 (shown dark in the
Figure) and rear
panel 52. Front panel 51 is designed to substantially cover the chest and
front are of the wearer,
and is fitted with selectively removable and attachable auxiliary panels 54.
Panel 51 is
constructed in the manner described elsewhere herein, with a substantially
soft, liquid resiytar~t,
floatable core covered front and back with, preferably, at least 10 individual
shield layers of
KEVLAR or SPECTRA. The cores (not shown) of front panel 51 and rear panel s?
are bctiv
water resistant and much lighter than water. The thickness of the core varies
in accordance wit::
the core material used and with the uses to which the flotation device is to
he put. It has been
found that in devices designed for the support of adult humans in water a two-
inch (2") thickness
of core material in the front panel gives excellent results, including both
protection of the wearer
from projectiles or other potentially penetrating objects and the provision of
substantial
buoyancy. Auxiliary panels 54 are attached to cover 50 in the front panel area
by means of h;.:ol:.
and loop fasteners, as drawn, but may be attached by any permanent or
detachable mechanisnn
known to the designer (although impermanent, renewable fastening is
preferred). Thev :~r,:.
depicted in "normal" wear positions at the bottom of the front of the
flotation device, at ahuu=,
16
CA 02298670 2000-O1-31
WO 99/06785 PCT/US98/15743
waist level of a typical wearer or user of the device. For maximum user
protection front panel
51 is integrally formed with rear panel- 52. In preferred embodiments rear
panel 52 also
incorporates a substantially soft., water resistant, buoyant core (not shown)
covered or wrapped
with at bast 10 individual shield layers; however, the rear panel core is
generally substantially
thinner than the front panel core, as it has been found that the provision of
greater buoyancy in
the front of such devices is generally an aid to wearers in the water. Thus,
for example, where
the front panel core has a thickness of two inches (2"), a one-inch ( 1 ")
core is typically found
sufFrcient for the back, both for flotation and projectile-stopping purposes.
The device is donned
by wrapping it around the torso of the user with his or her arms extending
through indentations
55 between the front and rear panels; fastening shoulder straps 56, which are
secured on the
front by hook-and-loop fasteners 59 and sewn permanently to the rear cover;
fastening side
fastener 57 (shown as hook and loop) and optional crotch support 58 (in the
manner of the
shoulder straps). Optional handle 9 is provided on head portion 53, typically
by sewing the
handle to the cover. The outside of cover 50 may also optionally include
pockets 60 (see Figures
5 and 6) for carrying emergency supplies and equipment, such as food,
flashlights, whistles, and
the like.
Figures 5 and b are perspective views of a preferred embodiment of the
personal flotation
device aspect of the invention, and illustrate use of auxiliary panels 54. In
Figure 5 the panels
are shown in a "stowed" position, with their bottom edges approximately even
with the bottom
edge of the flotation device, allowing maximum freedom of movement to wearer
99. In Figur;;
6, the auxiliary panels are deployed downward, providing impact- or projectile-
resistant
protection and additional flotation in the region of the wearer's hips, legs
and lower abdomen.
The auxiliary panels are depicted as attached to the flotation device by means
of hook and 1001
fasteners, mating parts 59 of which are located over a wide portion of cover
50 to allow
maximum flexibility in their deployment, and therefore in protective and
flo~ational options for
the wearer. With adaptable fasteners such as hook and loop fasteners,
auxiliary panels rrmy ~:vc~n
be turned sideways, as shown for the middle panel in Figure 6.
Figure 7a is a perspective view of a preferred briefcase embodiment of the
projectile
resistant shield aspect of the invention. Figure 7b is a cutaway view of a
preferred briefcase
embodiment of the projectile resistant shield of the invention. Briefcase 70
has compartments
17
CA 02298670 2000-O1-31
Vt~O 99/(16785 PCT/US98/15743
71 sized to accommodate protective or shield panels 5, one on each side of the
case. Panels 5
comprise multiple shield layers 21 wrapped about cores 3 and covered by
protective cover S0;
they are placed within compartments 71 to form a portable projectile- or
impact-resistant shield.
Optionally, one or more of panels 50 may simply be placed inside briefcase 70
and used in the
same way. Figures 7c, 7d, and 7e are schematic views showing the sizing and
use of a briefcase
embodiment ofthe projectile resistant shield ofthe invention. As shown in
Figure 7c, it has been
found that the vital organ cavity, including the ribcage, throat, and upper
abdomen and spinal
column, of most human beings may be covered by a panel measuring approximately
13 inches
by 17 inches (see rectangle 97). One of the purposes of the briefcase portable-
shield aspect of
the invention is to protect the organ cavity of its user; thus a preferred
size for briefcase shields
according to the invention is at least 13 by 17 inches. In Figure 7d it is
shown that a briefcase
of preferred dimensions may also be used to shield the organ cavity from the
side. In Figure 7e
user 98 is shown holding briefcase shield 70 to his chest in order to protect
his organ cavity.
Figure 8 is a perspective view of a preferred pontoon embodiment of the
projectile-
resistant structure aspect of the invention. Pontoon 80 is suitable for
emple~ment with a boat,
aircraft, or any other floating or marine structure, or on its own as buoy or
float. Pontoon 80
comprises cover 50 over a plurality of shield layers 20 wrapped around core 3,
which may
optionally comprise integral or embedded reinforcing structures, as will occur
to those skilled
in the art of designing marine structures. Attachments 6 are provided for
attaching the pontoon
to a structure, and if present may take any number of conventional forms, such
as weld tabs,
gussets, brackets, etc., attached by any conventional mechanical means.
Figures 9a and 9b are perspective views of marine applications of preferred
embodiments
of shield aspects of the invention. Figure 9a shows small boat 82
incorporating pontoons 80 to
provide primary flotation; in addition, panels 5 have been placed in various
locations abouT
control center 81 to protect operator 98. Panels 5 may be incorporated by
means of
conventional construction techniques inside the structure, or may be attached
directly to
bulkheads, wall, floors (or decks), or overheads by other conventional means.
Figure 9b shows
panels 5 used in similar fashion to protect high-occupancy regions of power
boat 83. Another
advantage afforded by the invention is that, in addition to increasing
projectile and impact
protection and providing buoyancy, panels 5 comprising foam according to the
invention may
18
CA 02298670 2000-O1-31
WO 99/06785 PCT/US98/15743
also be used to provide thermal insulation, as will occur to skilled
structural designers and
architects. -
Figure 10 is a perspective view of several preferred embodiments of the
projectile
resistant shield aspect of the invention incorporated in an automobile.
Automobile 10 has several
shield panels 5 attached to doors 84. As with the boats of Figure °,
panels S may b.
incorporated within or attached to the structures of automobile 10, using any
suitable
conventional technology. In addition to passenger cars, shield panels 10 might
be incorporated
in light or armored military vehicles, in armored cars used by banks, ete., in
delivery vans, or in
a wide variety of vehicular applications. Floors, doors, roofs, trunks, engine
compartments, and
other automotive features may be protected.
Figure I i is a perspective view of several preferred embodiments of the
projectile
resistant shield aspect of the invention incorporated in an aircraft. Aircraft
85 incorporates shield
panels 5 to protect pilots 98 in a similar manner to uses described in Figures
9 and 10. As in any
other structural applications, shield panels S may be employed to protect
sensitive or important
structure or equipment as well as people; for example, in vehicles and the
like shield panels might
be employed to protect computer installations or other electronic equipment,
such as radios er
radar; or, for example, in a passenger airliner they may be used to line
aircraft cargo holds or
other relatively high-risk locations in order to protect vital structure from
internal or cargo
explosions, terrorist acts, and the like.
Figure 12 is a perspective view of a preferred embodiment of the projectile-
resistant
shield panel aspect of the invention, and shows a preferred construction of
such a panel. A
plurality of shield layers 20 have been wrapped in the direction of arrows 31
around a double-
layer of impact-absorbent core 3, and cover 50 encompasses the entire
assembly. As shown in
the picture, several laminations of shield layers may be produced by means of
a single physic l
length of shield layer fabric or material, wrapped about on top of itself, and
ultimately sealed o=.'
seamed at one or more edges to keep the shield layers in place during service.
In embodimen~a
employing anisotropic shield layers, full advantage may be taken of the biased
or principal
characteristics of the properties of the anisotropic layers by wrapping to
several layers' thickness;
as shown in the Figure, using one or more separate lengths of shield material
or fabric, adding
19
CA 02298670 2000-O1-31
WO 99/06785 PCT/US98/15743
one or more additional layers by wrapping in an orthogonal direction
(indicated in the Figure bar
arrows 32) and, if desired, adding still fu --rther layers in the original or
any other direction.
With regard to systems and components above referred to, but not otherwise
specified
or described in detail herein, the workings and specifications of such systems
and components
and the manner in which they may be made or assembled or used, both
cooperatively with each
other and with the other elements of the invention described herein to effect
the purposes herein
disclosed, are all believed to be well within the knowledge of those skilled
in the art. _Na
concerted attempt to repeat here what is generally known to the artisan has
therefore been made.
In compliance with the statute, the invention has been described in language
more or leis
specific as to structural features. It is to be understood, however, that the
invention is nor
limited to the specific features shown, since the means and construction shown
comprise
preferred forms of putting the invention into effect. The invention is,
therefore, claimed in any
of its forms or modifications within the legitimate and valid scope of the
appended claims,
appropriately interpreted in accordance with the doctrine of equivalents.
IS
INDUSTRIAL APPLICABILITY
The invention has applicability to the field of protective shield structures,
and in particular
to soft armor made of laminated woven light-weight fiber materials. It
provides imprc~~ed
protection for people and other living things, for sensitive or rare
equipment, and for any oti;er
items under substantial risk of damage due to impact or projectiles.
