`
`
`(21) International Application Number: PCT/IL99/00260|(81) Designated States: AL, AM, AT, AU, AZ, BA, BB, BG, BR,
`
`BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD,
`
` (22) International Filing Date: 16 May 1999 (16.05.99)
`GE, GH, GM, HR, HU,ID, IL, IN, IS, JP, KE, KG, KP,
`KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK,
`MN, MW,MX, NO, NZ, PL, PT, RO, RU, SE, SG, SI, SK,
`
`SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZA, ZW,
`ARIPO patent (GH, GM, KE, LS, MW, SD, SL, SZ, UG,
`ZW), Eurasian patent (AM, AZ, BY, KG, KZ, MD, RU,TJ,
`
`TM), European patent (AT, BE, CH, CY, DE, DK,ES,FI,
`FR, GB, GR, JE, IT, LU, MC, NL, PT, SE), OAPI patent
`(BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE,
`SN, TD, TG).
`
`PCT
`
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`International Bureau
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`(51) International Patent Classification 6;
`(11) International Publication Number:
`F41H 5/04
`
`(43) International Publication Date:
`25 November 1999 (25.11.99)
`
`WO 99/60327
`
`
`(30) Priority Data:
`
`19 May 1998 (19.05.98)
`IL
`124543
`
`(71)(72) Applicant and Inventor: COHEN, Michael [IL/IL]; Kfar
`Etzion, 90912 Post North Yehuda (IL).
`
`
`
`(74) Agent: WOLFF, BREGMAN AND GOLLER; P.O. Box 1352,
`91013 Jerusalem (IL).
`
`Published
`With international search report.
`With amended claims.
`
`(54) Titles COMPOSITE ARMOR PLATE
`
`
`*%
`6
`«
`»
`\P
`
`
`SLIMONSS
`
`D>PIF ot
`DSAHOF 4
`
`PSOpyaOSSSSSSS
`SOSSSS SBPSOS OSES
`SOSOSSSSSSSSOSSSESS
`
`
`
`
`ZL)
`
`
`
`(57) Abstract
`
`The invention provides a composite armorplate (22) for absorbing and dissipating kinetic energy from high velocity projectiles, the
`plate comprising a single internal layer of pellets (24) which are directly bound and retained in plate form byasolidified material (16)
`such that the pellets are bound in a plurality of adjacent rows, characterized in that the pellets (24) 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
`aluminium oxide and ceramic material having an aluminium 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 the solidified material in the single internal layer of adjacent rows such that
`each of a majority of the pellets (24”) is in direct contact with at least 4 adjacentpellets (24’’) in the same layer to provide mutual lateral
`confinement therebetween, the pellets each have a substantially regular geometric form and thesolidified material and the plate are elastic.
`
`

`

`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCT on the front pages of pamphlets publishing international applications under the PCT.
`
`Zimbabwe
`
`Albania
`Armenia
`Austria
`Australia
`Azerbaijan
`Bosnia and Herzegovina
`Barbados
`Belgium
`Burkina Faso
`Bulgaria
`Benin
`Brazil
`Belarus
`Canada
`Central African Republic
`Congo
`Switzerland
`Céte d'Ivoire
`Cameroon
`China
`Cuba
`Czech Republic
`Germany
`Denmark
`Estonia
`
`ES
`FI
`FR
`GA
`GB
`GE
`GH
`GN
`GR
`HU
`IE
`IL
`18
`IT
`JP
`
`KG
`KP
`
`KR
`KZ
`Le
`LY
`LK
`LR
`
`Spain
`Finland
`France
`Gabon
`United Kingdom
`Georgia
`Ghana
`Guinea
`Greece
`Hungary
`Ireland
`Israel
`Iceland
`Italy
`Japan
`Kenya
`Kyrgyzstan
`Democratic People’s
`Republic of Korea
`Republic of Korea
`Kazakstan
`Saint Lucia
`Liechtenstein
`Sri Lanka
`Liberia
`
`LS
`LT
`LU
`LV
`MC
`
`MG
`MK
`
`ML
`MN
`MR
`MW
`MX
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`sD
`SE
`SG
`
`Lesotho
`Lithuania
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`Madagascar
`The former Yugoslav
`Republic of Macedonia
`Mali
`Mongolia
`Mauritania
`Malawi
`Mexico
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Singapore
`
`SI
`SK
`SN
`SZ
`TD
`TG
`TJ
`T™
`TR
`TT
`UA
`UG
`US
`UZ
`VN
`YU
`Zw
`
`Slovenia
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Turkmenistan
`Turkey
`Trinidad and Tobago
`Ukraine
`Uganda
`United States of America
`Uzbekistan
`Viet Nam
`Yugoslavia
`
`

`

`WO 99/60327
`
`PCT/IL99/00260
`
`COMPOSITE ARMOR PLATE
`
`The present invention relates to composite armor plates and panels. More
`
`particularly, the invention relates to an armored plate which may be wornto provide
`the user with lightweight ballistic protection, as well as to armored plates for
`
`providing ballistic protection for light and heavy mobile equipment and vehicles
`against high-speed projectiles or fragments.
`In US patent 5,763,813 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 boundin a plurality of superposed rows, characterized in
`
`that the pellets have an Al,0, 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 bysaid 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/m: and said solidified material and said plate are elastic.
`In European patent application Serial No. 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 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 Al,0, 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-98/15796 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
`
`

`

`WO 99/60327
`
`PCT/IL99/00260
`
`2
`
`the diameter D of said cylindrical body and the radius R of curvature of said at least
`one convexly curved end faceis at least 0.64:1.
`The teachings ofall three of these specifications is 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, wnose performanceis 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/m’.
`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 {000 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.
`Overly complex armor arrangements,
`A second consideration is cost.
`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 ofcivilian 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 andlight
`vehicle armor, which plates have been found to be vulnerable to damage from
`
`mechanical impacts caused by rocks, falls, etc.
`
`

`

`WO 99/60327
`
`PCT/IL99/00260
`
`3
`
`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 aluminium; 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
`
`armorincluding a hexagonal honeycomb core member.
`Other armor plate panels are disclosed in British Patents 1,081,464;
`
`4,352,418. 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.
`
`Ceramic materials are nonmetallic,
`
`inorganic solids having a crystalline or
`
`glassy structure, and have many useful physical properties, including resistance to
`heat, abrasion and compression, high rigidity, low weight in comparison with steel,
`
`and outstanding chemical stability. Such properties have long drawn the attention
`of armor designers, and solid ceramic plates, in thicknesses ranging from 7 mm. for
`personal protection to 30 mm.
`for heavy military vehicles, are commercially
`
`available for such use.
`
`Much research has been devoted to improving the low tensile and low
`
`flexible strength and poor fracture toughness of ceramic materials; however, these
`
`remain the major drawbacks to the use of ceramic plates and other
`
`large
`
`components which can crack and/or shatter in response to the shock of an
`
`incoming projectile.
`Light-weight, flexible armored articles of clothing have also been used for
`
`many decades, for personal protection against fire-arm projectiles and projectile
`splinters. Examples of this type of armor are found in U.S. Patent No. 4,090,005.
`Such clothing is certainly valuable against low-energy projectiles, such as those
`fired from a distance of several hundred meters, but fails to orotect the wearer
`against high-velocity projectiles originating at closer range and especially does not
`protect against armor-piercing projectiles.
`If made to provide such protection, the
`weight and/or cost of such clothing discourages its use. A further known problem
`
`with such clothing is that even when it succeeds in stopping a projectile the user
`
`may suffer injury due to indentation of the vest into the body, caused by too small a
`
`body area being impacted and required to absorb the energy of a bullet.
`
`

`

`WO 99/60327
`
`PCT/1L99/00260
`
`4
`
`A common problem with prior art ceramic armor concerns damage inflicted
`on the armor structure by a first projectile, whether stopped or penetrating. Such
`damage weakens the armor panel, and so allows penetration of a following
`projectile, impacting within a few centimeters of thefirst.
`The presentinvention is therefore intended to obviate the disadvantages of
`prior art ceramic armor, and inafirst embodiment to provide an armorplate which
`is effective against smail-caliber fire-arm projectiles, yet
`is of light weight, 1.e,
`having a weight of iess than 45 kg/m: (which is equivalent to about 9 Ibs/ft) and
`
`low bulk.
`in other embodiments the present invention provides an armorplate which is
`effective against a full range of armor-piercing projectiles from 5.56 mm and even
`up to 30 mm, as well as from normal smail-caliberfire-arm projectiles, yet is of light
`weight,
`i.e., having a weight of less than 185 kgim’. even for the heavier armor
`provided for dealing with 25 and 30 mm projectiles.
`A further object of the invention is to provide an armorplate or panel whichis
`particularly effective in arresting a plurality of armor-piercing projectiles impacting
`upon the same general areaof the panel.
`The
`armor plates described in US Patent 5,763,813 and European
`application 98301769.0 are made using ceramic pellets made substantially entirely
`of aluminum oxide.
`In WO-A-98/15796 the ceramic bodies are of substantially
`cylindrical shape having at least one convexly-curved end-face, and are preferably
`made of aluminium oxide.
`However,
`it has now been found that the improved properties of the plates
`described in the above patent applications
`is as much a function of
`the
`configuration of the pellets, which are of regular geometric form (for example, the
`pellets may be spherical or ovoidal, or of regular geometric cross-section, such as
`square, hexagonal, octagonal, or circular), 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 in
`the same layer to provide mutual
`lateral confinement therebetween. As a result,
`composite armor plates superior to those available in the prior art can be
`manufactured using glass pellets which have a specific gravity of only 2, or pellets
`
`

`

`WO 99/60327
`
`PCT/1L99/00260
`
`3
`
`made of sintered refractory materials or ceramic materials having a specific gravity
`equal to or below thatof aluminium 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.
`carbides and borides of magnesium,
`Thus,
`sintered oxides, nitrides,
`zirconium, tungsten, molybdium,
`titanium and silica can be used and especially
`preferred for use in the present
`invention are pellets selected from the group
`consisting of glass, boron carbide,
`titanium diboride, silicon carbide, magnesium
`oxide, silicon aluminum oxynitride in both its alpha and beta forms and mixtures
`
`thereof.
`With increase in specific gravity the stopping powerof the plates increases so
`that those plates utilizing pellets of higher specific gravity are also useful
`for
`absorbing anddissipating kinetic energy from high-velocity armor-piercing bullets.
`Accordingly,
`the present
`invention provides 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 aluminium oxide and
`ceramic material having an aluminium 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 4 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 preferred embodiments of the present invention at least a majority of said
`pellets have at least one convexly-curved end face orientedto substantially face in
`the direction of an outer impact receiving major surface of said plate, although
`pellets with flat or even concavely-curved end faces can also be used even though
`the same have been found to be lesseffective.
`
`

`

`WO 99/60327
`
`PCT/1L99/00260
`
`6
`
`In some preferred embodiments of the invention the majority of the pellets
`
`each have at least one axis having a length in the range of about 6-19 mm, and the
`total weight of said plate does not exceed 45 kg/m
`In other preferred embodiments of the invention the majority of said pellets
`
`each have at least one axis having a length in the range of from about 20 to 75 mm
`and the weight of said plate does not exceed 185 kg/m’.
`In especially preferred embodiments of the present
`
`invention, each of a
`
`majority of said pellets is in direct contact with at least six adjacent pellets.
`
`In a first preferred embodiment of the present
`
`invention said pellets are
`
`spherical.
`
`In a second preferred embodiment of the invention said pellets each
`
`have a major axis and said pellets are arranged with their major axes substantially
`
`parallel to each other and oriented substantially perpendicularly relative to said
`
`outer impact-receiving major surface of said panel.
`
`In especially preferred embodiments said pellets are other than cylindrical
`
`bodies having 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 faceis at least 0.64:1.
`
`The solidified material can be any suitable material which retains elasticity
`
`upon hardening at the thickness used, such as aluminium, epoxy, a thermoplastic
`
`polymer such as polycarbonate, or a thermoset plastic, thereby allowing curvature
`
`of the plate without cracking to match curved surfaces to be protected,
`
`including
`
`body surfaces, as well as elastic reaction of the plate to incoming projectiles to
`
`allow increased contact force between adjacentpellets at the point of impact.
`
`In French Patent 2,711,782, there is described a steel panel reinforced with
`
`ceramic materials; however, due to the rigidity and lack of elasticity. of the steel of
`
`said panel, said panei does not have the ability to deflect armor-piercing projectiles
`
`unless a thickness of about 8-9mm of steel
`
`is used, which adds undesirable
`
`excessive weight to the panel and further backing is also necessary thereby further
`
`increasing the weight thereof.
`
`It
`
`is further to be noted that the elasticity of the material used in preferred
`
`embodiments of the present invention serves,
`
`to a certain extent, to increase the
`
`

`

`WO 99/60327
`
`PCT/IL99/00260
`
`7
`
`thereby
`probability that a projectile will simultaneously impact several pellets,
`increasing the efficiency of the stopping powerof the plate of the present invention.
`
`there is provided a
`the invention,
`According to a further aspect of
`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 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 aluminium,
`
`titanium or woven or non-woventextile material.
`
`the
`In especially preferred embodiments of the multi-layered armor panel,
`inner layer adjacent to said outer layer comprises a tough woventextile 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 stapping 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 aluminium 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 powerof a plate constructed as described in said patentis not
`
`

`

`WO 99/60327
`
`PCT/IL99/00260
`
`8
`
`as good, weight for weight, as that of a plate in accordance with the present
`invention,
`in which each of the pellets is in direct contact with at least four and
`
`preferably six adjacentpellets.
`
`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
`
`In one embodiment, the ceramic balis are encased
`gaps for entry of molten metal.
`in a stainless steel wire screen; and in another embodiment, the composite armoris
`manufactured by adhering nickel-coated alumina spheres to an aluminium alloy
`plate by meansof a polysulfide adhesive. A composite armor plate as describedin
`
`this patent
`
`is difficult
`
`to manufacture because the ceramic spheres may be
`
`damaged by thermal shockarising 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 networkof 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 decreasesthe stopping powerthereof.
`
`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 powerthereof, due to a billiard-like effect upon impact.
`
`In U.S. Patents 3,523,057 and 5,134,725 there are described further
`
`armored panels incorporating ceramic and glass balls; however, said panels are
`flexible and it has been found that the flexibility of said panels substantially reduces
`their stopping strength upon impact, since the force of impact itself causes a flexing
`
`of said panels and a reduction of the supporting effect of adjacent constituent
`
`bodies on the impacted constituent body, due to the arrangement thereof in said
`
`patent. Thus,it will be noted that the teachings of U.S. Patent 5,134,725is 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
`
`

`

`WO 99/60327
`
`PCT/IL99/00260
`
`9
`
`arrangementis similar to that seen in US Patent 3,705,558. In addition, reference to
`Figures 3 and 4 of said patent showthatpellets of a first layer do not contact pellets
`of the same layer and 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 confinementof the pellets, as taught in the presentinvention.
`As will be realized, none of said prior art patents teaches or suggests the
`surprising and unexpected stopping power of a single layer of ceramic or glass
`pellets in direct contact with each other which, as will be shown hereinafter,
`successfully prevents penetration of fire-arm projectiles despite the relative light
`
`weight of the plate incorporating said pellets.
`Thus,
`it has been found that the novel armor of the present invention traps
`incoming projectiles between several pellets which are held in a single layer in
`mutual abutting and laterally-confining relationship. The relatively moderate size of
`the pellets ensures that the damage caused bya first projectile is localized and
`does not spread to adjoining areas, as in the case of ceramic plates.
`A major advantage of the novel approach provided by the present invention
`is that it enables the fabrication of different plates and panels adapted to deal with .
`
`different challenges, wherein e.g. smaller glass, sintered refractory or ceramic
`pellets can be used for personal armor and for meeting the challenge of 5.56, 7.62
`and 9 mm projectiles, while larger ceramic pellets can be used to deal with foreseen
`challenges presented by 14.5 mm, 25 mm and even 30 mm armor piercing
`
`projectiles.
`Thus it was found that cylindrical pellets having a diameter of 9.5 mm and a
`height of between 9.5 and 11.6 mm,as well as cylindrical pellets having a diameter
`of 12.7 mm and a height of between 9.5 and 11.6 mm were more than adequate to
`deal with projectiles of between 5.56 and 9 mm, whenarrangedin a plate according
`to the present invention.
`Similarly and as demonstrated hereinafter, spherical glass pellets having a
`diameter of 10 mm were more than adequate to deal with multi-impacts of soft metal
`
`component 5.56 and 7.62 mm projectiles.
`For heavy armored vehicles ceramic pellets having a diameter of 38 mm and
`a height of between 32 and 75 mm were found to be more than adequate to deal
`
`

`

`WO 99/60327
`
`PCT/1IL99/00260
`
`10
`
`with 20, 25 and even 30 mm armorpiercing projectiles when used in a multi-layered
`
`armor panel according to the presentinvention.
`An incoming projectile may contact the pellet array in one of three ways:
`4. 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 either spheres 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 and this form, when supported in a matrix of pellets, as
`shown, e.g. in the figures attached hereto, has been found to be significantly better
`at resisting shattering than other pellet arrangements suggestedin the priorart.
`2. Flankcontact. The impact causes projectile yaw and shattering,
`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 to
`form for itself a large aperture to penetrate, thus allowing the armor to absorb the
`
`projectile energy.
`The projectile is jammed, usually between the flanks of
`3. Valley contact.
`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
`matrix, and penetration is prevented.
`An additional preferred embodiment according to the present invention is one
`wherein the ceramic material
`is SiAION in its alpha structure of Sig,Ai,02Ne2,
`in
`
`.
`
`which “z’
`
`is a substitution coefficient of Al and O in the SisN4 and the “beta
`
`structure” of the formula MemivaSi12-(m+nAlmenOnNie-n, Wherein Me is a metal such as
`Li, Mg, Ca, Y, and lanthanide’s, m and n are substitution coefficients and val is the
`valency of the metal.
`
`The invention will now be described in connection with certain preferred
`
`embodiments with reference to the followingillustrative figures so that it may be
`
`more fully understood.
`it is stressed that the particulars
`With reference now to the figures in detail,
`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
`
`

`

`WO 99/60327
`
`PCT/IL99/00260
`
`il
`
`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 cross-sectional side view of a first preferred embodimentof a two-layered
`
`armor panel according to the invention;
`
`Figs. 2 is a perspective view of a small section of a second preferred embodiment
`
`of an armor panel according to the invention;
`
`There is seen in Fig.
`
`1 a composite armor plate 10 for absorbing and
`
`dissipating kinetic energy from fire-arm projectiles 12, said plate comprising a
`
`single internal layer of spherical glass pellets 14, said pellets being arranged in a
`
`single layer of adjacent rows, wherein each of a majority of said pellets is in direct
`
`contact with at least 4 adjacent pellets (as better seen with regard to the pellets
`
`shownin Fig. 2). As seen, the entire array of pellets is bound in said single layer of
`
`_
`
`a plurality of adjacent rows by solidified epoxy 16 and said plate 10 is further
`
`provided with an
`
`inner backing layer 18 made of DYNEEMA® or of similar material,
`
`to form a
`
`multi-layered armored panel 20.
`
`There is seen in Fig. 2 a composite armor plate 22 for absorbing and
`
`dissipating kinetic energy from fire-arm projectiles 12, said plate comprising a
`
`single internal layer of glass pellets 24 which are substantially cylindrical with at
`
`least one convexly-curved end face, said pellets being arrangedin a single layer of
`adjacent rows wherein each of a majority of said pellets 24’ js in direct contact with
`at least 4 adjacent pellets 24”. As shown, the entire array of pellets is bound in said
`
`single layer of a plurality of adjacent rows by solidified epoxy 16, and said plate 22
`
`is further provided with an inner backing layer 18 made of DYNEEMA®or of similar
`
`textile material such a backing made of polycarbonate,
`
`to form a multi-layered
`
`armored panel 26.
`
`

`

`WO 99/60327
`
`PCT/¥L99/00260
`
`12
`
`The nature of the solidified material 16 is selected in accordance with the
`
`weight, performance and cost considerations applicable to the intended use of the
`
`armor.
`
`Armor for land and sea vehicles is suitably made using a metal casting alloy
`
`least 80% aluminium. A suitable alloy is Aluminium Association
`containing at
`No. 535.0, which combines a high tensile strength of 35,000 kg/in? with excellent
`
`ductility, having 9% elongation. Further suitable alloys are of the type containing
`
`5% silicon B443.0. These alloys are easy to cast
`
`in thin sections;
`
`their poor
`
`machinability is of little concern in the application of the present invention. An
`
`epoxy or other plastic or polymeric material, advantageously fiber-reinforced,
`
`is
`
`also suitable.
`
`Tables 1 and 2 are reproductions of test reports relating to epoxy-bound
`
`multi-layer panels as described above with reference to Fig. 1. Each of the panels
`
`had dimensions
`
`of
`
`14”
`
`x
`
`14”
`
`and had a backing layer
`
`18 made
`
`of
`
`DYNEEMA® 10 mm thick..
`
`The first panel was impacted by a series of three soft-nosed component
`
`7.62 mm projectiles fired at 0° elevation and at a distance of 50 ft. from the target.
`
`Noneofthe 3 projectiles penetrated the panel.
`
`The second panel was impacted by a series of six soft-nosed component
`
`5.56 mm projectiles, also fired at 0 elevation and at a distance of 50 ft. from the
`
`target.
`
`Noneof the 6 projectiles penetrated the panel.
`
`Table 1
`
`
`H.P. WHITE LABORATORY,
`INC.
`
`DATA RECORD
`
`-BALLISTIC RESISTANCE TESTS
`
`Date Rec'd.
`
`04-27-98
`
`Via:
`
`Returned
`
`File (HPWLI)
`
`:
`
`:
`
`:
`
`Hand carried
`
`Hand carried
`
`RD-1.PIN
`
`Job No. :7592-02
`
`Test Date: 04-27-98
`
`Customer :R & D ETZION
`
`

`

`WO 99/60327
`
`PCT/IL99/00260
`
`13
`
`TEST PANEL
`
`Description: PROPRIETARY
`
`Manufacturer: R & D ETZION
`
`Sample No.
`
`: 12
`
`Size
`
`: PT.10X12 VT. 14X14 in. Weight
`
`: PT. 5.18, VT. 1.97 Ibs.
`
`Thicknesses: na
`
`Avg. Thick.
`
`: na
`
`Hardness
`
`<na
`
`Plies/Laminates: NA
`
`AMMUNITION
`
`(1): 7.62x51mm M80 BALL 149.0gr
`
`Lot No.: WINCHESTER WCC90B001-001
`
`(2):
`(3):
`(4):
`
`Lot No.:
`Lot No.:
`Lot No.:
`SET-UP
`
`Veil. Screens
`
`: 6.5 ft. & 9.5 ft.
`
`Rangeto Target : 50.0 ft.
`
`Shot Spacing : PER CUSTOMER REQUEST
`
`Range Number: 1
`
`Barrel No./Gun: 062
`
`Obliquity
`
`: 0 deg.
`
`Witness Panel : CLAY
`
`Backing material: 5.5” CLAY/PLYWOOD
`