|Publication number||USH1567 H|
|Application number||US 04/667,624|
|Publication date||Aug 6, 1996|
|Filing date||Sep 7, 1967|
|Priority date||Sep 7, 1967|
|Publication number||04667624, 667624, US H1567 H, US H1567H, US-H-H1567, USH1567 H, USH1567H|
|Inventors||Gordon R. Parsons, Fred E. Mooney|
|Original Assignee||The United States Of America As Represented By The Secretary Of The Army|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (5), Referenced by (45), Classifications (9)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.
Heretofore, significant advances in transparent armor have been attained by the geometrical arrangement of commercially available materials such as hard glasses, chemically-tempered glasses, thermoset biaxially stretched acrylics, polycarbonates, etc. Utilizing these material composites with areal densities of 10 to 11 pounds have attained merit ratings of about 1.40 against caliber .30 BALL M2 projectiles at 0° obliquity, while, caliber 30 AP M2 projectiles have been defeated at 0° obliquity utilizing these materials with areal densities of approximately 20 lbs to show merit ratings of 1.10 to 1.36. These composites have areal densities which are unacceptable to military requirements, particularly for aircraft applications, and for that reason have not been incorporated in armor systems. Further, transparent composites that defeat caliber .50 BALL M2 and AP M2 projectiles are nonexistent, yet non-combat vehicles are increasingly subjected to these threats.
Present day combat has necessitated a change in tactics to cope with guerilla warfare and has resulted in stringent requirements affecting the design of air and land vehicles. Non-combat vehicles are often subjected to spasmodic combat conditions and thus now receive armor considerations. The role of the helicopter as a combat vehicle has stimulated concern of its vulunerability to small arms fire, which includes engines, fuel tanks, gear drives and crew personnel. With mobility being a prime requisite for the present day army, the ability to navigate, which depends on visibility becomes increasingly important. Yet, the development of suitable and efficient transparent protective material lags greatly behind that of opaque armor.
However, nearly all transparent materials have been deficient in that they have only a limited capability for inducing fracture of small arms armorpiercing projectiles, which is the criterion in determining favorable ballistic performance. Attempts to obtain stress-wave reinforcement of stresses in the projectile by variation of composite glass frontal layer thickness have been singularly unsuccessful. It appears that available glasses do not have sufficient strength or modulus to induce high amplitude stress pulses in the projectiles.
It is therefore, the object of this invention to provide a transparent composite (ceramic-glass-plastic), capable of defeating caliber .30 AP M2 projectiles at 0° obliquity, with 8 to 10 pounds areal density and caliber .50 AP M2 projectiles with an areal density of 18-20 pounds, which would not only decrease the vulnerability of vehicles of all types but would establish a technological milestone in the field of transparent armor.
The means, by which the selection of materials by properties and proper geometric arrangement for maximum ballistic protection, are the result of intensive investigation of the pressure wave transfer through ceramic composites impacted by steel cored projectiles. Theoretical and experimental conclusions indicate the fundamental material properties, modulus of elasticity and density, are favorable to ballistic protection when a high elastic modulus and low density facing material is utilized ia conjunction with a low elastic modulus and low density back-up material.
Expressions employed herein are defined as follows:
Areal density: armor weight expressed in pounds per square foot of surface area ##EQU1## where both the experimental and standard armors have the same areal density (lbs./sq. ft.)
AP: armor piercing
V50 penetration: is a term used to indicate that there is a 50:50 chance of penetration
Elastic Modulus: is the ratio of stress to strain within the elastic range of a particular material and the elastic range is the limit to which a particular material may be subjected and still return to its original form or shape.
This invention attains its stated object by the formation of a transparent composite consisting of a single ply transparent ceramic face plate,since the required property of high elastic modulus is more characteristic of ceramics than glass, and also of low density with the general overall characteristic of being relatively hard and brittle, while thee transparent back-up layer or layers is of low elastic moduli, of low density and also of relatively tough resilient material. The face plate and the back-up plate of one or more layers are bonded together by any suitable transparent adhesive to form the desired composite.
Variations of the composite are illustrated in the drawing in which:
FIG. 1 is a perspective view in section of a three layered transparent composite and
FIG. 2 is a similar view in section of the composite utilizing two layers.
The transparent composite shown in FIG. 1 consists of a front face 10 of spinel plate (by weight substantially 71.5% AL203.28,5% MgO) with a thickness of 3/8", an intermediate layer 11 of sheets of polysulfone or other suitable transparent plastic material of 1/8"hot pressed together to form a tough resilient layer with a thickness of 1/2" and a 1/4" back layer 12 of polycarbonate known under the trade name of "Lexan" which is even more resilient than intermediate layer. When the layers are assembled, the face plate 10 is bonded to the intermediate layer 11 with a 0.0250" sheet of polyvinyl butyral and the back layer 12 is bonded to the layer 11 with a suitable cellulose acetate pressure sensitive adhesive and the configuration is subjected to heat and pressure to form the composite shown. It should be noted that the plates as well as the bonding means are all transparent. It is essential that the ceramic face plate be of high elastic modulus and that the modulus of elasticity decreases from front to back in the composite with the back-plate being of low elastic modulus and all three layers being of as low a density as compatible with the aim of ballistic protection, because the other result sought is that the composite be light enough to be utilized on airborne vehicles. This composite varies in thickness from 1" to 11/2" and will defeat small arms ammunition up through and including caliber .30 AP M2 projectiles.
FIG. 2 shows a light weight transparent composite for defeating all small arms ammunition up through and including caliber .50 AP M2 projectiles, wherein the 1/2" face plate 13 may be spinel plate, of the composition set forth above and the back-up layer or layers 14 with an overall thickness of 1" to 11/4" and which may be made up singly or several combinations as interlayers or laminated sheets of the same material or cast in place. This back-up layer 14 as in the composite in FIG. 1, should be of low elastic modulus and of low density. The back-up layer or plate 14 may be composed of various transparent thermoplastic or thermosetting composition selected from the following.
Cellulose acetate butyrate
Cellulose acetate propionate
Acrylics and modified acrylics
Epoxy-rigid and flexible
Ionomers-"Surlyn A" (DuPont trade mark)
Phenolics transparent (thermosetting)
Polyurethanes (thermoplastic and thermosetting)
The ballistic protection afforded by these composites from experimental test data are as follows.
Projectile--caliber .30 AP M2
Areal Density--12 lbs/ft2
Ballistic Limit--2930 ft/sec for V50 penetration
The thickness of each component and subsequently the entire composite will vary according to the specific materials utilized and the type of projectiles the armor is designed to defeat. In general, the composite thickness should vary between 1" and 11/4" for defeating caliber .30 AP M2 projectiles and between 11/2" to 13/4 to defeat caliber .50 AP M2 projectiles.
The areal density of these composites should vary from 8 to 10 pounds for defeating caliber .30 AP M2 projectiles at 0° obliquity and from 18 to 20 pounds for defeating caliber .50 AP M2 projectiles at 0° obliquity.
The transparent adhesive employed in effectively bonding the laminae together are readily available from various manufacturers. The bonding adhesive is applied in a manner well known in the art and is followed by curing at elevated temperatures and pressures which will vary according to the type of resin employed.
In the foregoing, the preferred embodiment of this invention has been disclosed. However, it is not intended that this invention be so limited to the specific examples set forth above, as it will be apparent to those skilled in the art, that the ingredients may be varied and a variety of equivalent substances may be employed without departing from the spirit of the invention or exceeding the scope of the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US1223135 *||Apr 25, 1914||Apr 17, 1917||Abel Bardin||Multiple-plate reinforced glass and process of producing same.|
|US1423652 *||Aug 18, 1921||Jul 25, 1922||American Abrasive Metals Compa||Plate for resisting flame and cutting tools|
|US3083123 *||Jun 1, 1960||Mar 26, 1963||Gen Electric||Magnesia alumina spinel articles and process of preparing same|
|US3516839 *||Sep 1, 1967||Jun 23, 1970||Gen Electric||Transparent magnesia-alumina spinel and method|
|US3634177 *||Nov 1, 1966||Jan 11, 1972||Gen Electric||Lightweight transparent penetration-resistant structure|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US6860186 *||Dec 18, 2002||Mar 1, 2005||Michael Cohen||Ceramic bodies and ballistic armor incorporating the same|
|US7472637||Nov 14, 2005||Jan 6, 2009||Massachusetts Institute Of Technology||Hierarchical material assemblies and articles for use in projectile impact protection|
|US7681485||Nov 16, 2006||Mar 23, 2010||American Development Group International, Llc||Transparent ballistic resistant armor|
|US7770506||Jun 10, 2005||Aug 10, 2010||Bae Systems Tactical Vehicle Systems Lp||Armored cab for vehicles|
|US7861638 *||Apr 16, 2007||Jan 4, 2011||Defbar Systems Llc||Transparent blast and ballistic projectile resistant barrier|
|US7895932 *||Oct 19, 2007||Mar 1, 2011||D&O Innovations, LLC||Optically clear turret dome, and combined turret shroud|
|US7954416 *||Sep 21, 2006||Jun 7, 2011||Cosimo Cioffi||Bullet-proof structure|
|US8028612||Mar 12, 2010||Oct 4, 2011||American Development Group International, Llc||Transparent ballistic resistant armor|
|US8066319 *||Nov 14, 2007||Nov 29, 2011||Bae Systems Land & Armaments, L.P.||Vehicle emergency egress assembly|
|US8161862 *||Oct 11, 2007||Apr 24, 2012||Corning Incorporated||Hybrid laminated transparent armor|
|US8176828||Jan 7, 2009||May 15, 2012||Schott Corporation||Glass-ceramic with laminates|
|US8176829||Jan 29, 2009||May 15, 2012||Schott Corporation||Armor system and method of manufacture|
|US8176831||Apr 10, 2009||May 15, 2012||Nova Research, Inc.||Armor plate|
|US8267001 *||Dec 4, 2007||Sep 18, 2012||Battelle Memorial Institute||Composite armor and method for making composite armor|
|US8382191||Oct 24, 2011||Feb 26, 2013||BAE Systems Land & Armamnets, L.P.||Vehicle emergency egress assembly|
|US8544376||Dec 29, 2011||Oct 1, 2013||Schott Corporation||Glass-ceramic with laminates|
|US8603616||Mar 20, 2008||Dec 10, 2013||Schott Corporation||Lightweight transparent armor window|
|US8632120||Nov 23, 2011||Jan 21, 2014||Bae Systems Land & Armaments L.P.||Universal latch mechanism|
|US8695476||Mar 14, 2011||Apr 15, 2014||The United States Of America, As Represented By The Secretary Of The Navy||Armor plate with shock wave absorbing properties|
|US8833233 *||Jun 12, 2009||Sep 16, 2014||Krd Sicherheitstechnik Gmbh||Bullet-resistant transparent laminate composite and protection arrangement having a bullet-resistant transparent laminate composite|
|US9091510 *||Mar 21, 2007||Jul 28, 2015||Schott Corporation||Transparent armor system and method of manufacture|
|US9157703||Mar 29, 2012||Oct 13, 2015||Am General Llc||Transparent Armor Structure|
|US20030221547 *||May 28, 2002||Dec 4, 2003||Asher Peretz||Lightweight armor plates, systems including same and methods of use thereof|
|US20060249012 *||Nov 14, 2005||Nov 9, 2006||Sai Sarva||Hierarchical material assemblies and articles for use in projectile impact protection|
|US20070283801 *||Jun 9, 2006||Dec 13, 2007||Armorsmith Company||Armor apparatus and method|
|US20080314237 *||Sep 21, 2006||Dec 25, 2008||Cosimo Cioffi||Bullet-Proof Structure|
|US20090217813 *||Jan 7, 2009||Sep 3, 2009||John Carberry||Glass-Ceramic with laminates|
|US20090320675 *||Apr 22, 2008||Dec 31, 2009||Landingham Richard L||Mosaic Transparent Armor|
|US20100031810 *||Nov 16, 2006||Feb 11, 2010||Neal Murray L||Transparent ballistic resistant armor|
|US20100043630 *||Dec 4, 2007||Feb 25, 2010||Jay Sayre||Composite Armor and Method for Making Composite Armor|
|US20100257997 *||Apr 10, 2009||Oct 14, 2010||NOVA Research, Inc||Armor Plate|
|US20100330341 *||Apr 16, 2007||Dec 30, 2010||Defbar Systems Llc||Transparent blast and ballistic projectile resistant barrier|
|US20110017053 *||Mar 12, 2010||Jan 27, 2011||American Development Group International, Llc||Transparent ballistic resistant armor|
|US20110088541 *||Sep 29, 2010||Apr 21, 2011||Linda Ruth Pinckney||Transparent armour having improved ballistic properties|
|US20110185884 *||Jun 12, 2009||Aug 4, 2011||Esw Gmbh||Bullet-resistant transparent laminate composite and protection arrangement having a bullet-resistant transparent laminate composite|
|US20110203452 *||Feb 19, 2010||Aug 25, 2011||Nova Research, Inc.||Armor plate|
|US20120291621 *||Dec 7, 2010||Nov 22, 2012||Battelle Memorial Institute||Composite armor and method for making composite armor|
|US20140290473 *||Jun 20, 2012||Oct 2, 2014||Bayer Materialscience Llc||Polycarbonate laminate for close-proximity blast events|
|EP1166031A1 †||Nov 12, 1999||Jan 2, 2002||Rafael - Armament Development Authority Ltd.||Ballistic armor panel|
|EP2275770A1||Jun 9, 2006||Jan 19, 2011||Saint-Gobain Ceramics and Plastics, Inc.||Transparent ceramic composite|
|EP2275772A1||Jun 9, 2006||Jan 19, 2011||Saint-Gobain Ceramics and Plastics, Inc.||Transparent ceramic composite|
|EP2699405A4 *||Apr 20, 2012||May 13, 2015||Schott Corp||Light weight temperature resistant transparent laminate structure|
|WO2008147391A2 *||Oct 30, 2007||Dec 4, 2008||Neal Murray L||Transparent ballistic resistant armor|
|WO2010080699A1 *||Jan 7, 2010||Jul 15, 2010||Schott Diamondview Armor Products, Llc||Transparent armor system and method of manufacture|
|WO2012145664A1 *||Apr 20, 2012||Oct 26, 2012||Schott Corporation||Light weight temperature resistant transparent laminate structure|
|U.S. Classification||89/36.02, 428/911, 501/153|
|International Classification||F41H5/04, B32B27/06|
|Cooperative Classification||F41H5/0407, B32B27/06|
|European Classification||B32B27/06, F41H5/04B|