Note: Descriptions are shown in the official language in which they were submitted.
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CERAMIC BODIES AND BALLISTIC ARMOR
INCORPORATING THE SAME
The present invention relates to a ceramic body for deployment in a
composite armor panel, for absorbing and dissipating kinetic energy from
projectiles and for ballistic armor panels incorporating the same. More
particularly, the invention relates to improved ceramic bodies for use in
structural armored plates for providing ballistic protection for light and
heavy
mobile equipment and for vehicles against high-velocity projectiles or
fragments.
The present invention is a modification of the inventions described in
European patent application 96308166.6 (EP-A-0843149), European patent
application 98301769.0, and International patent application
PCTIGB97/02743 (WO-A-98/15796), WO 99/60327 and W099/53260.
In EP-A-0843149 there is described a composite armor plate for
absorbing and dissipating kinetic energy from high velocity, armor-piercing
projectiles, said plate comprising a single internal layer of high density
ceramic pellets which are directly bound and retained in plate form by a
solidified material such that the pellets are bound in a plurality of
superposed
rows, characterized in that the pellets have an A1203 content of at least 85%,
preferably at least 93%, and a specific gravity of at least 2.5, the majority
of
the pellets each have at least one axis in the range of about 3-12 mm, and
are bound by said solidified material in a single internal layer of superposed
rows, wherein a majority of each of said pellets is in direct contact with at
least 4 adjacent pellets, the total weight of said plate does not exceed 45
kg/m2 and said solidified material and said plate are elastic.
In European patent application 98301769.0 there is described and
claimed a composite armor plate for absorbing and dissipating kinetic energy
from high velocity, armor-piercing projectiles, said plate comprising a single
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internal layer of high density ceramic pellets which are directly bound and
retained in plate form by a solidified material such that the pellets are
bound
in a plurality of adjacent rows, characterized in that the pellets have an
A1203
content of at least 93% and a specific gravity of at least 2.5, the majority
of
the pellets each have at least one axis of at least 12 mm length and are
bound by said solidified material in a single internal layer of adjacent rows,
wherein a majority of each of said pellets is in direct contact with at least
4
adjacent pellets, and said solidified material and said plate are elastic.
In WO-A-9815796 there is described and claimed a ceramic body for
deployment in a composite armor panel, said body being substantially
cylindrical in shape, with at least one convexly curved end face, wherein the
ratio D/R between the diameter D of said cylindrical body and the radius R of
curvature of said at least one convexly curved end face is at least 0.64:1.
In WO 99/60327 there is described and claimed a composite armor
plate for absorbing and dissipating kinetic energy from high velocity
projectiles, said plate comprising a single internal layer of pellets which
are
directly bound and retained in plate form by a solidified material such that
the
pellets are bound in a plurality of adjacent rows, characterized in that the
pellets have a specific gravity of at least 2 and are made of a material
selected from the group consisting of glass, sintered refractory material,
ceramic material which does not contain aluminum oxide and ceramic
material having an aluminum oxide content of not more than 80%, the
majority of the pellets each have at least one axis of at least 3 mm length
and
are bound by said solidified material in said single internal layer of
adjacent
rows such that each of a majority of said pellets is in direct contact with at
least six adjacent pellets in the same layer to provide mutual lateral
confinement therebetween, said pellets each have a substantially regular
geometric form and said solidified material and said plate are elastic.
In WO 99/53260 there is described and claimed a composite armor
plate for absorbing and dissipating kinetic energy from high velocity,
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armor-piercing projectiles, as well as from soft-nosed projectiles, said plate
comprising a single internal layer of high density ceramic pellets,
characterized in that said pellets are arranged in a single layer of adjacent
rows and columns, wherein a majority of each of said pellets is in direct
contact with at least four adjacent pellets and each of said pellets are
substantially cylindrical in shape with at least one convexly-curved end face,
further characterized in that spaces formed between said adjacent cylindrical
pellets are filled with a material for preventing the flow of soft metal from
impacting projectiles through said spaces, said material being in the form of
a
triangular insert having concave sides complimentary to the convex curvature
of the sides of three adjacent cylindrical pellets, or being integrally formed
as
part of a special interstices-filling pellet, said pellet being in the form of
a six
sided star with concave sides complimentary to the convex curvature of the
sides of six adjacent cylindrical pellets, said pellets and material being
bound
and retained in plate form by a solidified material, wherein said solidified
material and said plate material are elastic.
The teachings of all five of these specifications are incorporated herein
by reference.
There are four main considerations concerning protective armor
panels. The first consideration is weight. Protective armor for heavy but
mobile military equipment, such as tanks and large ships, is known. Such
armor usually comprises a thick layer of alloy steel, which is intended to
provide protection against heavy and explosive projectiles. However,
reduction of weight of armor, even in heavy equipment, is an advantage since
it reduces the strain on all the components of the vehicle. Furthermore, such
armor is quite unsuitable for light vehicles such as automobiles, jeeps, light
boats, or aircraft, whose performance is compromised by steel panels having
a thickness of more than a few millimeters, since each millimeter of steel
adds a weight factor of 7.8 kg/m2.
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Armor for light vehicles is expected to prevent penetration of bullets of
any type, even when impacting at a speed in the range of 700 to 1000 meters
per second. However, due to weight constraints it is difficult to protect
light
vehicles from high caliber armor-piercing projectiles, e.g. of 12.7 and 14.5
mm, since the weight of standard armor to withstand such projectile is such
as to impede the mobility and performance of such vehicles.
A second consideration is cost. Overly complex armor arrangements,
particularly those depending entirely on synthetic fibers, can be responsible
for a notable proportion of the total vehicle cost, and can make. its
manufacture non-profitable.
A third consideration in armor design is compactness. A thick armor
panel, including air spaces between its various layers, increases the target
profile of the vehicle. In the case of civilian retrofitted armored
automobiles
which are outfitted with internal armor, there is simply no room for a thick
panel in most of the areas requiring protection.
A fourth consideration relates to ceramic plates used for personal and
light vehicle armor, which plates have been found to be vulnerable to damage
from mechanical impacts caused by rocks, falls, etc.
Fairly recent examples of armor systems are described in U.S. Patent
No. 4,836,084, disclosing an armor plate composite including a supporting
plate consisting of an open honeycomb structure of aluminum; and U.S.
Patent No. 4,868,040, disclosing an antiballistic composite armor including a
shock-absorbing layer. Also of interest is U.S. Patent 4,529,640, disclosing
spaced armor including a hexagonal honeycomb core member.
Other armor plate panels are disclosed in British Patents 1,081,464;
1,352,418; 2,272,272, and in U.S. Patent 4,061,815 wherein the use of
sintered refractory material, as well as the use of ceramic materials, are
described.
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According to the present invention there is now provided a ceramic body for
deployment in a composite armor panel, for absorbing and dissipating kinetic
energy from high velocity projectiles, said body having a peg-like
configuration consisting of a stem section and a head section wherein a
cross-sectional area across said stem is less than a cross-sectional area
across said head section.
In preferred embodiments of the present invention, said stem section
has a regular geometric cross-section and especially preferred is a stem
section with a circular cross-section or a regular polygonal cross-section
such
as a hexagonal cross-section.
In further preferred embodiments of the present invention, said head
section also has a regular geometric cross-section and especially preferred is
a stem section with a circular cross-section or a regular polygonal
cross-section such as a hexagonal cross-section.
While the head and stem sections can have the same, but differently
sized, cross-section, this is not necessarily the case and, e.g., a body with
a
stem of circular cross-section and a head of hexagonal cross-section can
also be molded for use in the present invention.
In a further aspect of the present invention, there is provided a ballistic,
armor panel for absorbing and dissipating kinetic energy from high velocity
projectiles, said panel comprising:
a plurality of ceramic bodies, each of said bodies having a peg-like
configuration consisting of a stem section and a head section wherein a
cross-sectional area across said stem is less than a cross-sectional area
across said head section; and a substrate for assembling said bodies in a
close-packed, single layer array, such that each of a majority of said bodies
is
positioned with its head section in direct contact with the head section of at
least four and preferably six adjacent bodies and the stems of said bodies are
supported and held by said substrate.
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In especially preferred embodiments of the present invention there is
provided a ballistic armor panel for absorbing and dissipating kinetic energy
from high velocity projectiles, said panel comprising-
a plurality of ceramic bodies, each of said bodies having a peg-like
configuration consisting of a stem section and a head section wherein a
cross-sectional area across said stem is less than a cross-sectional area
across said head section; and
a plate member having a plurality of openings, each of said opening sized to
receive a stem section of a body with the underside of the head section of
said body overriding the periphery of said opening, such that each of a
majority of said bodies is positioned with its, head section in direct contact
with the head section of at least four and preferably six adjacent bodies
inserted in said plate.
The armor plates described in EP-A-0843149 and European patent
application 98301769.0 are made using ceramic pellets made substantially
entirely of aluminum oxide. In WO-A-9815796 the ceramic bodies are of
substantially cylindrical shape having at least one convexly-curved end-face,
and are preferably made of aluminum oxide.
In WO 99/60327 it was described that the improved properties of the
plates described in the earlier patent applications of this series is as much
a
function of the configuration of the pellets, which are of regular geometric
form with at least one convexly-curved end face (for example, the pellets may
be spherical or ovoidal, or of regular geometric cross-section, such as
hexagonal, with at least one convexly-curved end face), said panels and their
arrangement as a single internal layer of pellets bound by an elastic
solidified
material, wherein each of a majority of said pellets is in direct contact with
at
least four adjacent pellets and said curved end face of each pellet is
oriented
to substantially face in the direction of an outer impact-receiving major
surface of the plate. As a result, said specification teaches that composite
armor plates superior to those available in the prior art can be manufactured
using pellets made of sintered refractory materials or ceramic materials
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having a specific gravity below that of aluminum oxide, e.g., boron carbide
with a specific gravity of 2.45, silicon carbide with a specific gravity of
3.2 and
silicon aluminum oxynitride with a specific gravity of about 3.2.
Thus, it was described in said publication that sintered oxides, nitrides,
carbides and borides of magnesium, zirconium, tungsten, molybdenum,
titanium and silica can be used and especially preferred for use in said
publication and also in the present invention the ceramic bodies utilized
herein are formed of a ceramic material selected from the group consisting of
sintered oxide, nitrides, carbides and borides of alumina, magnesium,
zirconium, tungsten, molybdenum, titanium and silica.
More particularly, the present invention relates to a ceramic body as
defined for absorbing and dissipating kinetic energy from high velocity armor
piercing projectiles, wherein said body is made of a material selected from
the group consisting of alumina, boron carbide, boron nitride, titanium
dib.oride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide,
silicon aluminum oxynitride and mixtures thereof.
In USSN 09/924745 there is described and claimed a composite armor
plate for . absorbing and dissipating kinetic energy from high velocity
projectiles, said plate comprising a single internal layer of pellets which
are
directly bound and retained in plate form by a solidified material such that
the
pellets are bound in a plurality of adjacent rows, said pellets having a
specific
gravity of at least 2 and being made of a material selected from the group
consisting of glass, sintered refractory material and ceramic material, the
majority of the pellets each having at least one axis of at least 3 mm length
and being bound by said solidified material in said single internal layer of
adjacent rows such that each of a majority of said pellets is in direct
contact
with six adjacent pellets in the same layer to provide mutual lateral
confinement therebetween, said pellets each having a substantially regular
geometric form, wherein said solidified material and said plate are elastic,
characterized in that a channel is provided in each of a plurality of said
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pellets, substantially opposite to an outer impact-receiving major surface of
said plate, thereby reducing the weight per area of each of said pellets.
In preferred embodiments described therein each of said channels
occupies a volume of up to 25% within its respective pellet.
Said channels can be bored into preformed pellets or the pellets
themselves can be pressed with said channel already incorporated therein.
Thus, in preferred embodiments of the present invention a channel is
provided in said body to reduce the weight per area thereof and preferably
said channel occupies a volume of up to 25% of said body.
In accordance with the present invention said channels are preferably
of a shape selected from the group consisting of cylindrical, pyramidal,
hemispherical and quadratic, hexagonal prism and combinations thereof.
As is known, there exists a ballistic effect known in the art in which a
projectile striking a cylinder at an angle has a tendency to move this
cylinder
out of alignment causing a theoretical possibility that a second shot would.
have more penetration effect on a panel.
As will be realized, since material is removed from the pellets of the
present invention their weight is decreased, as is the overall weight of the
entire composite armor plate from which they are formed, thereby providing
the unexpected improvement of reduced weight of protective armor panels
without loss of stopping power, as shown in the examples hereinafter.
In preferred embodiments of the present invention said pellets each
have a major axis and said pellets are arranged with their major axes
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substantially parallel to each other and oriented substantially
perpendicularly
relative to said outer impact-receiving major surface of said panel.
In a most preferred embodiment of the present invention a ballistic
armor panel as defined herein is provided for incorporation in an opening
provided in an armored vehicle.
Thus the present invention also provides an armored vehicle having
ballistic armor panels according to the present invention incorporated
therein.
In further embodiments of the present invention the ceramic bodies of
the present invention are constructed of transparent ceramic material.
In especially preferred embodiments of the present invention the plate
member utilized in the ballistic armor panel is formed from a plurality of
interconnected rings which optionally are further bound together by a
solidified material.
The solidified material can be any suitable material, such as aluminum,
a thermoplastic polymer such as polycarbonate, or a thermoset plastic such
as epoxy.
In French Patent 2,711,782, there is described a steel panel reinforced.
with ceramic materials; however said panel does not have the ability to
deflect armor-piercing projectiles unless a thickness of about 8-9 mm of steel
is used, which adds undesirable excessive weight to the panel and further
backing is also necessary thereby further increasing the weight thereof.
According to a further aspect of the invention, there is provided a
multi-layered armor panel, comprising an outer, impact-receiving layer formed
by a composite armor plate as hereinbefore defined for deforming and
shattering an impacting high velocity projectile; and an inner layer adjacent
to
said outer layer and, comprising an elastic material for absorbing the
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remaining kinetic energy from said fragments. Said elastic material will be
chosen according to cost and weight considerations and can be made of any
suitable material, such as aluminum or woven or non-woven textile material.
In especially preferred embodiments of the multi-layered armor panel,
the inner layer adjacent to said outer layer comprises a tough woven textile
material for causing an asymmetric deformation of the remaining fragments of
said projectile and for absorbing the remaining kinetic energy from said
fragments, said multi-layered panel being capable of stopping three
projectiles fired sequentially at a triangular area of said multi-layered
panel,
wherein the height of said triangle is substantially equal to three times the
length of the axis of said pellets.
As described, e.g., in U .S. Patent 5,361,678, composite armor plate
comprising a mass of spherical ceramic balls distributed in an aluminum alloy
matrix is known in the prior art. However, such prior art composite armor
plate
suffers from one or more serious disadvantages, making it difficult to
manufacture and less than entirely suitable for the purpose of defeating metal
projectiles. More particularly, in the armor plate described in said patent,
the
ceramic balls are coated with a binder material containing ceramic particles,
the coating having a thickness of between 0.76 and 1.5 and being provided to
help protect the ceramic cores from damage due to thermal shock when.
pouring the molten matrix material during manufacture of the plate. However,,
the coating serves to separate the harder ceramic cores of the balls from
each other, and will act to dampen the moment of energy which is transferred
and hence shared between the balls in response to an impact from a bullet or
other projectile. Because of this and also because the material of the coating
is inherently less hard than that of the ceramic cores, the stopping power of
a
plate constructed as described in said patent is not as good, weight for
weight, as that of a plate in accordance with the present invention, in which
the head of each of the bodies is in direct contact with six adjacent bodies.
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U.S. Patent 3,705,558 discloses a lightweight armor plate comprising a
layer of ceramic balls. The ceramic balls are in contact with each other and
leave small gaps for entry of molten metal. In one embodiment, the ceramic
balls are encased in a stainless steel wire screen; and in another
embodiment, the composite armor is manufactured by adhering nickel-coated
alumina spheres to an aluminum alloy plate by means of a polysulfide
adhesive. A composite armor plate as described in this patent is difficult to
manufacture because the ceramic spheres may be damaged by thermal
shock arising from molten metal contact. The ceramic spheres are, also
sometimes displaced during casting of molten metal into interstices between
the spheres.
In order to minimize such displacement, U.S. Patents 4,534,266 and
4,945,814 propose a network of interlinked metal shells to encase ceramic
inserts during casting of molten metal. After the metal solidifies, the metal
shells are incorporated into the composite armor. It has been determined,
however, that such . a network of interlinked metal shells substantially
increases the overall weight of the armored panel and decreases the
stopping power thereof.
It is further to be noted that U.S. Patent 3,705,558 suggests and
teaches an array of ceramic balls disposed in contacting pyramidal
relationship, which arrangement also substantially increases the overall,
weight of the armored panel and decreases the stopping power thereof, due
to a billiard-like effect upon impact.
In U.S. Patent 5,134,725 there are described armored panels
incorporating ceramic and glass balls. It will be noted that the teachings of
U.S. Patent 5,134,725 is limited to an armor plate having a plurality of
constituent bodies of glass or ceramic material which are arranged in at least
two superimposed layers, which arrangement is similar to that seen in
US Patent 3,705,558. In addition, reference to Figures 3 and 4 of said patent
show that pellets of a first layer do not contact pellets of the same layer
and
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are only in contact with pellets of an adjacent layer and therefore do not
benefit from the support of adjacent pellets in the same layer to provide
mutual lateral confinement of the pellets, as taught in the present invention.
As will be realized in the preferred embodies of the present invention
there is provided a structural, load-bearing ballistic armor wherein the plate
member having a plurality of. openings provides the structural framework
while the peg-like configuration of the ceramic bodies of the present
invention
assure that the bodies are still in direct contact with each other via their
head
sections thereby providing mutual lateral confinement and reinforcement not
available in armor wherein the pellets are separated by a rigid honey-comb
array.
Thus, it has been found that the novel armor of the present invention
traps incoming projectiles between several pellets which are held with their
head sections in a single layer in rigid mutual abutting and laterally-
confining
relationship.
An incoming projectile may contact the pellet array in one of three
ways:
1. Center contact. The impact allows the full volume of the pellet to
participate in stopping the projectile, which cannot penetrate without
pulverizing the whole pellet, an energy-intensive task. The pellets used are
preferably of circular or hexagonal cross-section or other regular geometric
shapes having at least one convexly-curved end face, said end face being
oriented to substantially face in the direction of an outer impact receiving
major surface of said plate.
2. Flank contact. The impact causes projectile yaw, thus making
projectile arrest easier, as a larger frontal area is contacted, and not only
the
sharp nose of the projectile. The projectile is deflected sideways and needs
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to form for itself a large aperture to penetrate, thus allowing the armor to
absorb the projectile energy.
3. Valley contact. The projectile is jammed, usually between the
flanks of three pellets, all of which participate in projectile arrest. The
high
side forces applied to the pellets are resisted by the pellets adjacent
thereto
as held by the substrate or plate, and penetration is prevented.
The invention will now be described in connection with certain
preferred embodiments with reference to the following illustrative figures so
that it may be more fully understood.
With reference now to the figures in detail, it is stressed that the
particulars shown are by way of example and for purposes of illustrative
discussion of the preferred embodiments of the present invention only, and
are presented in the cause of providing what is believed to be the most useful
and readily understood description of the principles and conceptual aspects
of the invention. In this regard, no attempt is made to show structural
details
of the invention in more detail than is necessary for a fundamental
understanding of the invention, the description taken with the drawings
making apparent to those skilled in the art how the several forms of the
invention may be embodied in practice.
In the drawings:
FIG. 1 is a perspective view of a preferred embodiment of the ceramic body
according to the invention;
FIG. 2 is an elevational view of a similar ceramic body provided with convex
ends;
FIG. 3 is a perspective view of an embodiment provided with a hexagonal
head;
FIG. 4 is a perspective view of an embodiment provided with a prismatic stem
section;
FIG. 5 is a perspective view of a ceramic body having a square head;
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FIG. 6a is a perspective view of a ballistic armor panel constructed using the
ceramic body seen in FIG. 3;
FIG. 6b is an elevational view of the panel seen in FIG. 6a;
FIG. 7 is a perspective view of a panel built using the ceramic body seen in
FIG. 2;
FIG. 8 is a perspective view of an armor panel built using a ceramic body
similar to that shown in FIG. 3, the head section end being convex;
FIG. 9 is a partially-sectioned elevational view of a ceramic body having a
weight-deducing slot;
FIG. 10 is a fragmented perspective view of a further embodiment of a
ballistic armor panel; and
FIGS. 11 and 11a are schematic illustrations of an armored vehicle
incorporating a panel of the present invention.
There is seen in FIG. 1 a ceramic body 10 intended for deployment in a
composite armor panel. Examples of several such panels will be shown
starting with FIG. 6a. The panel is designed for absorbing and dissipating
kinetic energy from high velocity projectiles, such as rifle fire and small
shell
fragments.
The body 10 has a peg-like configuration consisting of a stem section 12 and
a head section 14. As can be seen, a cross-sectional area across the stem
section 12 is less than a cross-sectional area across the head section 14.
In the preferred embodiment seen in the figure, the stem section 12 has a.
regular geometric cross-section, which in this case is circular. In the
present
embodiment the head section also has a circular cross-section, and a flat top
face 16.
The body 10 is formed of a ceramic material. Preferred ceramics are sintered
oxide, nitrides, carbides and borides of alumina, magnesium, zirconium,
tungsten, molybdenum, titanium and silica.
Where the pellet is intended to be used for absorbing and dissipating kinetic
energy from armor piercing projectiles, other materials are preferred. These
materials are typically alumina, boron carbide, boron nitride, titanium
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diboride, silicon carbide, silicon oxide, silicon nitride, magnesium oxide,
silicon aluminum oxynitride and mixtures thereof.
FIG. 2 illustrates a ceramic body 18 wherein the head section 20 is provided
with a convex head face 22 and a convex end face 24. The convex head
shape 22 encourages sideways deflection of bullets impacting the pellet
head. Thus the projectile is stopped as explained above regarding "Flank
Contact".
The convex end face 24 facilitates assembly of the body 18 into an armor
panel, which will be seen in FIG. 7.
Referring now to FIG. 3, there is depicted a ceramic body 26 wherein the
head section 28 has a regular geometric cross-section; in the present
embodiment the head section is hexagonal.
The armor panel resulting from use of this arrangement will be described with
reference to FIG. 6b.
FIG. 4 illustrates a further embodiment of a ceramic body 30 wherein also the
stem section 32 has a regular polygonal cross-section. Such configuration is
useful in applications where it is advantageous to prevent the rotation of the
body if the head section 34 is impacted by a high-velocity fragment.
Seen in FIG. 5 is a ceramic body 36 wherein the head section 38 has a.
regular polygonal cross-section, in the present embodiment this being
square. As in previous embodiments the body has a peg-like configuration
consisting of a stem section 40 and a head section 38. The cross-sectional
area across the stem section 40 is less than the cross-sectional area across
the head section 38.
Referring now to FIGS. 6a and 6b, there is depicted a ballistic armor panel 42
for absorbing and dissipating kinetic energy from high velocity projectiles.
The outer face 44 of the panel 42 comprises a large number of ceramic
bodies 26, as described with reference to FIG. 3.
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The ceramic bodies 26 are inserted and held in a close-packed, single layer
array 46. Excepting the ceramic bodies 26' around the outer borders of the
panel, each body 26 is positioned with its head section 28 in direct contact
with the head section 28 of six adjacent bodies 26. Thus the ceramic bodies
provide mutual lateral confinement and reinforcement, which is important for
retaining stopping power after a first projectile has impacted the panel 42
resulting in some damage to the ceramic body 26 which was hit.
The stems 12 of the bodies 26 are supported and held by the substrate 50.
FIG. 7 shows a further ballistic armor panel 52 for absorbing and dissipating
kinetic energy from high velocity projectiles.
A plurality of ceramic bodies 18 are seen, as described with reference to
FIG. 2.
The bodies 18 are retained in a plate member 54 having many openings 56,
each opening being sized to receive the stem section 58 of one of the
ceramic bodies. The underside 60 of the head section 20 of the body 18
overrides the periphery of the opening 56.
Except for the outer edges 62 of the armor panel 52, each body is positioned
with its head section 20 in direct contact with six adjacent bodies 18
inserted
in the plate member 54.
Turning now to FIG. 8, there is seen a ballistic armor panel faced with
ceramic bodies 68. The body 68 is similar to the body 26 seen in FIG. 3,
except that the head of the body 68 is convex.
The plate member 70 is formed from a plurality of interconnected rings 72.
The rings 72 can be mass produced using dedicated tooling therefor.
Advantageously the rings 72 are further bound together by a solidified
material 74, for example aluminum, or a thermoplastic polymer such as
polycarbonate, or a thermoset plastic such as epoxy.
FIG 9 shows a further embodiment of a ceramic body 76. The body 76 is
similar to the body 18 seen in FIG. 2. An important feature of body 76 is a
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channel 78 provided in the body to reduce the weight per area thereof.
Suitably, the channel 78 occupies a volume of up to 25% of the body 76.
The body 76 is particularly useful for airborne use and for personal
applications.
Referring now to FIG.10, there is seen a further embodiment of a ballistic
armor panel 80. The panel 80 has an inner 82 and an outer 84 surface, the
outer surface 84 facing the impact side. Ceramic bodies 36 are arranged in a
plurality of adjacent rows. The axes of the stems sections 40 of the bodies 36
are substantially parallel with each other and perpendicular to the surfaces
of
the panels 82, 84.
Preferably the inner layer 82 is formed from a plurality of adjacent layers
82',
82", each layer comprising a plurality of unidirectional coplanar anti-
ballistic
fibers embedded in a polymeric matrix. Advantageously, the fibers of adjacent
layers 82', 82", are oriented at an angle of between about 450 to 90 to each
other.
In operation the outer, impact-receiving layer deforms and shatters an
impacting high velocity projectile. The inner layer, being elastic, is then
able
to absorb the remaining kinetic energy from the projectile fragments. The.
elastic material is chosen according to cost and weight considerations
applicable to the designated application. Although any suitable material can
be used, such as aluminum or woven or non-woven textile material, the
preference is for at least 90% Aramide fiber, fiber orientation being as
described. The final material selection is based on meeting weight and
volume restraints at lowest cost.
Referring now to FIGS. 11 and 11 a there is seen an armored vehicle 86
wherein a panel 88 of the present invention has been provided in an opening
(not shown) of said vehicle, the panel 88, in the embodiment shown,
incorporating ceramic bodies 90 having cylindrical heads and cylindrical
stems, said panel being shown in an enlarged detail view in FIG. 11 a.
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As will be realized since the panels of the present invention are lighter in
weight then steel panels of comparable size and provide even better
protection it is advantageous to incorporate several panels according to the
present invention in such vehicles in place of standard steel armor in order
to
reduce the overall weight of the vehicle.
As is known transparent ceramic material is available as described e.g., in
H1567 and H1519 and such material could be used in the panels of the
present invention.
In order to establish the effectiveness of the ceramic bodies of the present
invention and composite armor panels incorporating the same a panel was
prepared with the size of 10 X 12 in. and ceramic bodies having a cylindrical
stem and hexagonal head section with a convexly curved end face as
illustrated in FIG. 8 was prepared and sent to the H.P. White Laboratory, Inc.
in Maryland for ballistic resistance testing.
The description of the test and the results are set forth hereinafter.
CA 02439183 2003-09-02
19
7 S ANf
Manuisrak-`E 1GV 5Vm31e W.:;_!?~A
see ^ ~veznnt : 7, 2Q i8s. oa m 4ad;.: a,/0a/C~
1Gs1_~n.
7~icRnor.ua 0.,4 ; 9. A.92C, 0.513, 0.409 it `letanves N.A Va S.trNO C.+R:? =i
O
'tirs2amin~tas NA =at lnad r'
a.q. Thick.: 3,91 tn,
~acctituicn . P=4CPR1 VT:.RY
SET-UP ?nmzryVel.4aoe,c: 15.,3 ft.,
Shat sq-e;n4: PER C1J TGMER , .='OU =3 T ?nmary vaf.i.wUCn : 2Y.Q T. 'r m
iWtL")B F 73
w(uw:: r and 3.020", ^_C24-T3 1,L'UMINUM Ac~.,wc veo. Scearnc v:1 as 34.17 in.
1'(5
caiquiev 0 deg. n'oadtrd Vci. Ucaticn NA R' 32'.4
3aainng MA ft-4u is Tatga -ts.a $ 3a t mczaC n t+ ES 7 5.LRREL
. latptiai - -
ccnwiti.winq:AME31ZNT Taywto WA.:n"".Q in. cwamat: FU LA
Areotaet: PCCL,
,%MMUt4rr)CN
(1) : 7.83mm AP, 41E1, 150 gr. :ct Nom: Q1 =N 38
rn. LtNo.:
. -Cj !GA$LE STANCARCS CR ?RGCECUREE
(1) PS21 CUSTCME.R R .CUE37
(1)
Sna An.. "met vew~ty t J Yma : Vetoc+y Z inq. vv . Vct. _-es slnio Vc~
Pw+etrat an ?uowotc
.YO. iuwd (Ns) ! (u-.ce) (tltal dw_) , (!us) ! (NC) I .. .._- .
1 1 7087 2822 7C91 22C0 29?1 1 15 I 23C5 Nana
2 1 7115 2311 7113 2810 2313 13 27Y5 None
3 1 7092 2323 7932 2320 2320 1F 2804 Ncne
4 1 7131 2235 7-37 2302 2 -03 15 278E Nana
7 7.79 2225 7022 22924 2_25 { 13 2309 None
a t 7095 2819 7258 2313 2918 15 2803 Nona
As will be noted said panel having a weight of only 7.2 pounds
provided exceptional multi-impact performance wherein none of the 7.62 X 51
mm, 150 grain, armor piercing, M61 projectiles fired at a distance of 45 feet
from the target penetrated said panel.
CA 02439183 2003-09-02
It will be evident to those skilled in the art that the invention is not
limited to the details of the foregoing illustrative embodiments and that the
present invention may be embodied in other specific forms without departing
from the spirit or essential attributes thereof. The present embodiments are
therefore to be considered in all respects as illustrative and not
restrictive,
the scope of the invention being indicated by the appended claims rather
than by the foregoing description, and all changes which come within the
meaning and range of equivalency of the claims are therefore intended to be
embraced therein.
