Patent Publication Number: US-2004055501-A1

Title: Penetrator and method for using same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     [0001] This application is related to an application entitled “A Penetrator and Method of Using Same” by inventors Hunn, Banks, and Cowan, filed on Sep. 20, 2002 and having attorney docket number 2063.004900/VS-592. 
    
    
     
       BACKGROUND OF THE INVENTION  
       [0002] 1. Field of the Invention  
       [0003] This invention relates to a penetrator and a method of using the penetrator, and, more particularly, to a penetrator for penetrating and damaging a variety of different types of targets.  
       [0004] 2. Description of the Related Art  
       [0005] Flechettes generally are small, dart-like, projectiles that are typically dispensed at high velocities and in large numbers to damage various types of targets. As they are unpowered and have no explosive elements, they rely on kinetic energy as the damage mechanism. They are generally designed to have minimum aerodynamic drag so that they can travel over long distances at high velocities with good accuracy. Flechettes may be individually dispensed from a gun, dispensed in numbers from a gun in a shotgun-like manner, or dispensed in numbers from a warhead of a rocket or missile.  
       [0006] Flechettes are typically designed with the intended target in mind. For example, some flechettes are designed to behave as hardened penetrators to breach harder targets, such as thin armor. Such flechettes are less effective against softer targets because they tend to pass through the target quickly with minimal damage. Other flechettes are designed to damage softer targets by fracturing or bending as they strike the target; however, they are often ineffective against harder targets because of the tendency to fracture or bend upon striking such targets.  
       [0007] In combat situations wherein both harder and softer targets are anticipated, flechettes for each type of target have conventionally been needed. Supplying, storing, and deploying multiple types of flechettes based upon the perceived or anticipated target may lead to logistical difficulties. Other conventional approaches to damaging both harder and softer targets have included the use of other types of penetrators, often having explosive components, which are more expensive to deploy than flechette-based weapons.  
       [0008] The present invention is directed to overcoming, or at least reducing, the effects of one or more of the problems set forth above.  
       SUMMARY OF THE INVENTION  
       [0009] In one aspect of the present invention, a penetrator is provided. The penetrator includes a fore body having a center of aerodynamic pressure forward of a center of gravity and a stabilizing portion removably attached to the fore body such that, when attached to the fore body, a center of gravity for the penetrator is forward of a center of aerodynamic pressure for the penetrator.  
       [0010] In another aspect of the present invention, a vehicle is provided. The vehicle includes a body, means for propelling the vehicle, and a plurality of penetrators disposed within the body and dispensable therefrom. At least one of the plurality of penetrators includes a fore body having a center of aerodynamic pressure forward of a center of gravity and a stabilizing portion removably attached to the fore body such that, when attached to the fore body, a center of gravity for the penetrator is forward of a center of aerodynamic pressure for the penetrator.  
       [0011] In yet another aspect of the present invention, a cartridge is provided. The cartridge includes a casing, an explosive charge disposed within the casing, a primer proximate the explosive charge, and at least one penetrator disposed within the casing forward of the explosive charge. The at least one penetrator includes a fore body having a center of aerodynamic pressure forward of a center of gravity and a stabilizing portion removably attached to the fore body such that, when attached to the fore body, a center of gravity for the penetrator is forward of a center of aerodynamic pressure for the penetrator.  
       [0012] In another aspect of the present invention, a method of using a penetrator is provided. The method includes propelling the penetrator toward a first target, penetrating the first target with a fore body of the penetrator, and detaching a stabilizing portion of the penetrator from the fore body. The method further includes impacting the second target with the fore body.  
       [0013] In yet another aspect of the present invention, a penetrator is provided. The penetrator includes means for penetrating a target having a center of aerodynamic pressure forward of a center of gravity, means for aerodynamically stabilizing the penetrator, and means for removably attaching the means for penetrating the target and the means for aerodynamically stabilizing the penetrator, wherein a center of gravity for the penetrator is forward of a center of aerodynamic pressure for the penetrator when the means for penetrating the target is attached to the means for aerodynamically stabilizing the penetrator. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0014] The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which the leftmost significant digit(s) in the reference numerals denote(s) the first figure in which the respective reference numerals appear, and in which:  
     [0015]FIG. 1A is an exploded side view of a penetrator according to the present invention;  
     [0016]FIG. 1B is an exploded side view of the penetrator of FIG. 1A including an alternative pin and blind bore;  
     [0017] FIGS.  1 C- 1 G are side views of stabilizing portions alternative to that of FIGS. 1A and 1B;  
     [0018]FIG. 2A is an assembled side view of the penetrator of FIGS. 1A and 1B;  
     [0019]FIG. 2B is a cross-sectional view of the penetrator of FIG. 2 taken along the line  2 B- 2 B;  
     [0020] FIGS.  3 A- 3 F are stylized diagrams illustrating a use of the penetrator of FIGS.  1 - 3  according to the present invention;  
     [0021] FIGS.  4 A- 4 B are stylized diagrams illustrating propelling the penetrator of FIGS.  1 - 3  from a gun;  
     [0022]FIG. 5A is a stylized diagram of a cartridge including the penetrator of FIGS.  1 - 3 ;  
     [0023]FIGS. 5B and 5C are stylized diagrams illustrating propelling the penetrator of FIGS.  1 - 3  from the cartridge of FIG. 5A disposed within a gun;  
     [0024] FIGS.  6 A- 6 B are stylized diagrams illustrating dispensing a plurality of the penetrators of FIGS.  1 - 3  from an airborne vehicle. 
    
    
     [0025] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.  
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS  
     [0026] Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developer&#39;s specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.  
     [0027]FIG. 1A provides an exploded view of an illustrative embodiment of the present invention. A penetrator  100  includes a fore body  102  coupled with a stabilizing portion  104 . In the illustrated embodiment, the fore body  102  comprises a nose portion  106  shaped to decrease aerodynamic drag on the penetrator  100  when assembled with the stabilizing portion  104  and to augment the hard target piercing capability of the penetrator  100 . However, the invention is not so limited. Rather, the fore body  102  in general, and the nose portion  106  in particular, may have any chosen shape. Thus, by way of example and illustration, the fore body  102  is but one means for penetrating the target  302 . Moving aftward along the fore body  102 , the nose portion  106  transitions to a body portion  108 , which has an outer diameter generally corresponding to that of a forward end  110  of the stabilizing portion  104  to decrease aerodynamic drag on the penetrator  100 . However, the scope of the present invention is not so limited, but rather the body portion  108  and the forward end  110  of the stabilizing portion  104  may have any chosen dimensions and/or shapes.  
     [0028] In the illustrated embodiment, the fore body  102  further includes a pin  112  extending aftward from the body portion  108 . When assembled, the pin  112  is received in a blind bore  114  defined by the stabilizing portion  104  to couple the fore body  102  and the stabilizing portion  104 , as shown in FIG. 2A. In one embodiment, the pin  112  is adhesively bonded within the bore  114  by an adhesive layer  116 , shown in FIG. 2B. Alternatively, the pin  112  may have a press-fit relationship with the bore  114  and, in such an embodiment, the adhesive layer  116  is omitted. The scope of the present invention, however, encompasses any means for coupling the fore body  102  and the stabilizing portion  104 , so long as the stabilizing portion  104  may be detached from the penetrator  100  as it encounters a target, as will be described later.  
     [0029] For example, the pin  112  may be part of the stabilizing portion  104  and the fore body  102  may define the bore  114 , in which the pin is received. Alternatively, the pin  112  may be a separate element and each of the fore body  102  and the stabilizing portion  104  may define a bore (e.g., the bore  114 ) therein. In such an embodiment, the pin  112  would be received in both of the bores. Alternatively, other mechanical elements and/or interconnections may be used to detachably couple the fore body  102  and the stabilizing portion  104 , and such mechanical elements and/or interconnections are considered to be within the scope of the present invention.  
     [0030] For example, as shown in FIG. 1B, an alternative fore body  102   a  includes a pin  124  (as an alternative to the pin  112  of FIG. 1A) extending aftward from the body portion  108 . When assembled, the pin  124  is received in a blind bore  126  (as an alternative to the blind bore  114  of FIG. 1A) defined by an alternative stabilizing portion  104   a . The pin  124  comprises grooves  124   a ,  124   b  that engage protrusions  126   a ,  126   b  of the blind bore  126  to detachably couple the fore body  102   a  with the stabilizing portion  104   a . In one embodiment, the pin  124  and the blind bore  126  are sized and configured such that the pin  124  may be snapped into and out of the blind bore  126 . Thus, by way of example and illustration, each of the pins  112 ,  124  is but one means for removably attaching the fore body  102   a  and the stabilizing portion  104   a.    
     [0031] Referring again to FIGS. 1A and 1B, the stabilizing portion  104  provides aerodynamic stability to the penetrator  100  and, in one embodiment, comprises outwardly extending fins  118 . While the illustrated embodiment includes the stabilizing portion  104  having three fins  116 , the present invention is not so limited. Rather, the scope of the present invention includes a stabilizing portion (e.g., the stabilizing portion  104 ) having a plurality of fins of any chosen number. For example, an alternative embodiment of the present invention may include a stabilizing portion having four fins.  
     [0032] In fact, the scope of the present invention includes a stabilizing portion comprising any means for improving the aerodynamic stability of the penetrator  100 . For example, as shown in FIG. 1C, a stabilizing portion  104   c  includes a tuft  128  disposed proximate an aft end  129  of the stabilizing portion  104   c . In the illustrated embodiment, the tuft  128  may comprise a mass of randomly oriented fibers made of cotton, fiberglass, or the like. Further, as illustrated in FIG. 1D, a stabilizing portion  104   d  may comprise an outwardly sloping flare  130  for improving the aerodynamic stability of the penetrator  100 . Alternatively, as shown in FIG. 1E, a stabilizing portion  104   e  may comprise a plurality of outwardly and aftwardly extending flaps  132  for improving the aerodynamic stability of the penetrator  100 .  
     [0033] Further, as illustrated in FIG. 1F, a stabilizing portion  104   f  includes a balloon  134  disposed proximate an aft end  129  of the stabilizing portion  104   f  for improving the aerodynamic stability of the penetrator  100 . The balloon  134  may be made of a rubber, nylon cloth, or any other chosen material capable of inhibiting a flow of air therethrough.  
     [0034] Alternatively, as shown in FIG. 1G, a stabilizing portion  104   g  includes a ribbon  136  disposed proximate an aft end  129  of the stabilizing portion  104   g  for improving the aerodynamic stability of the penetrator  100 . The ribbon  136  may be made, for example, of fiberglass cloth, nylon cloth, or the like. Thus, by way of example and illustration, each of the stabilizing portions  104  and  104   a - 104   g  is but one means for aerodynamically stabilizing the penetrator  100 . While the following description of the invention is provided relating to the stabilizing portion  104 , the description applies equally to penetrators comprising any of the stabilizing portions  104   a - 104   g.    
     [0035] In the illustrated embodiment, the fore body  102  comprises a material having a higher density than a material comprising the stabilizing portion  104 . For example, in one embodiment, the fore body  102  may comprise tungsten, a tungsten alloy, an iron alloy, or steel, and the stabilizing portion  104  may comprise a polymeric material (e.g., an epoxy material or a urethane material), aluminum, an aluminum alloy, magnesium, or a magnesium alloy. The higher density material aids the fore body  102  in penetrating harder targets, such as armor plate, while the lower density material of the stabilizing portion  104  decreases the overall weight of the penetrator  100  and aids in achieving aerodynamic stability.  
     [0036] Generally, if a penetrator is to be aerodynamically stable, it is necessary for the center of gravity of the penetrator to be forward of the center of aerodynamic pressure of the penetrator. The “center of gravity” can be considered to be the point where all the weight of a penetrator can be considered to be concentrated. The “center of aerodynamic pressure” can be considered to be the point on a penetrator at which the total aerodynamic force effectively acts.  
     [0037] As indicated above, if the center of gravity of the penetrator is forward of the penetrator&#39;s center of aerodynamic pressure, the penetrator is considered to be aerodynamically stable. If, however, the center of gravity of the penetrator is aft of its center of aerodynamic pressure, the penetrator is considered to be unstable and will skew or tumble as it travels through a medium, such as air. Referring again to FIG. 2A, the center of gravity of the penetrator  100  is indicated generally at  202  and the center of aerodynamic pressure of the penetrator  100  is indicated generally at  204 . With the center of gravity  202  being forward of the center of aerodynamic pressure  204 , the penetrator  100  is considered to be aerodynamically stable. As will be appreciated by those skilled in the art having the benefit of this disclosure, the precise location of the center of gravity  202  and center of aerodynamic pressure  204  will be implementation specific, depending upon the overall design of the penetrator  100 .  
     [0038] FIGS.  3 A- 3 F illustrate the penetrator  100  in one particular use. FIG. 3A shows the penetrator  100  advancing toward (as indicated by an arrow  304 ) a first target  302 . The first target is a “hard” target, such as an armor plate that might be used to protect a vehicle from combat damage. FIG. 3B illustrates the fore body  102  penetrating the first target  302 .  
     [0039] As the penetrator  100  advances through the first target  302 , the stabilizing portion  104  becomes wedged therein and separates from the fore body  102 , as shown in FIG. 3C. In one embodiment, the adhesive layer  200  (shown in FIG. 2B) fractures as a result of the impact between the stabilizing portion  104  and the first target  302  to detach the stabilizing portion  104  from the fore body  102 . In another embodiment, the pin  112  fractures as a result of the impact between the stabilizing portion  104  and the first target  302  to detach the stabilizing portion  104  from the fore body  102 . In an embodiment wherein the fore body  102  comprises the pin  124  (as shown in FIG. 1B), the pin  124  is released from the blind bore  126  as a result of the impact between the stabilizing portion  104  and the first target  302 . After separating from the stabilizing portion  104 , the fore body  102  continues to travel beyond the first target  302 .  
     [0040] However, as the stabilizing portion  104  is removed, the aerodynamic stability of the penetrator  100  changes. The spatial relationship between the center of gravity and the center of pressure of the fore body  102  is different than that for the fore body  102  and the stabilizing portion  104  together. Referring again to FIG. 1A, the center of gravity of the fore body  102  is indicated generally at  120  and the center of aerodynamic pressure of the fore body  102  is indicated generally at  122 . As the center of aerodynamic pressure  122  is forward of the center of gravity  120 , the fore body  102  is considered aerodynamically unstable. Upon removal of the stabilizing portion, the center of aerodynamic pressure  122  moves forward of the center of gravity  120  in a manner not shown, and the penetrator becomes aerodynamically unstable. Thus, the forward portion (i.e., the fore body  102 ) of the penetrator  100  begins to skew or tumble when the stabilizing portion  104  is removed.  
     [0041] Referring now to FIG. 3D, as the fore body  102  travels beyond the first target  302 , it begins to skew or tumble from its previous spatial orientation (as indicated by arrows  306   a ,  306   b ) due to its aerodynamic instability. While FIG. 3D illustrates the fore body  102  tumbling in a clockwise direction, the fore body  102  may tumble in one or more directions in three-dimensional space over time as it travels through the air.  
     [0042]FIG. 3E illustrates the skewing or tumbling fore body  102  approaching a second target  308 . The second target  308  is a “soft” target, such as the vehicle or equipment shielded by the first target  302  (e.g., the armor plate). As the fore body  102  skews or tumbles, it is likely that it will impact the second target  308  at an attitude other than in a “head-on” attitude, in which the nose portion  106  is forward and a central axis  310  of the fore body  102  is generally perpendicular to the second target  308 . Thus, the fore body  102  in a non-head-on attitude impacts a larger area of the second target  308  than if the fore body  102  were in a head-on attitude, which will increase the amount of damage the fore body  102  may inflict on the second target  308 .  
     [0043]FIG. 3F illustrates the impact of the fore body  102  with the second target  308 , producing an opening  312  therethrough and debris  314 . Depending upon the construction of the second target  308  and the attitude at which the fore body  102  impacts the second target  308 , the fore body  102  may break into a plurality of pieces, as shown in FIG. 3F, or may remain generally intact.  
     [0044] FIGS.  3 G- 3 L illustrate the penetrator  100  in an alternative use, in which the fore body  102  additionally encounters an intermediate target  316  disposed between the first target  302  and the second target  308 . The intermediate target  316  is a hard target, but is generally softer than the first target  302 . In one embodiment, after the stabilizing portion  104  has separated from the fore body  102  (as shown in FIG. 3C), the fore body  102  travels toward the intermediate target  316  generally in an unskewed condition, as shown in FIG. 3G, or only marginally skewed. For example, the fore body  102  may not be skewed or may be only marginally skewed because the velocity of the fore body  102  may have been reduced, due to the impact with the first target, such that the fore body  102  is marginally aerodynamically stable. Further, the viscosity of the medium through which the fore body  102  is traveling may be insufficiently viscous to cause skewing thereof. Generally, a medium that is more viscous will induce more skewing or tumbling than a medium that is less viscous.  
     [0045] Thus, the fore body  102  encounters and penetrates the intermediate target  316  in generally a head-on attitude, as shown in FIG. 3H. In one embodiment, as shown in FIG. 3I, the fore body  102  skews or tumbles, as described in reference to FIG. 3D, as it travels toward the second target  308 . FIG. 3J illustrates the impact of the fore body  102  with the second target  308 , producing the opening  312  therethrough and the debris  314 . Depending upon the construction of the second target  308  and the attitude at which the fore body  102  impacts the second target  308 , the fore body  102  may break into a plurality of pieces, as shown in FIG. 3J, or may remain generally intact.  
     [0046] Alternatively, in one embodiment, the fore body  102  may remain generally unskewed or only marginally skewed after penetrating the intermediate target  316 , as shown in FIG. 3K. The fore body  102  may remain generally unskewed or only marginally skewed as discussed above regarding FIG. 3G. As the fore body  102  impacts the second target  308 , it skews or tumbles and penetrates the second target  308 , as shown in FIG. 3L. The fore body  102  may become skewed or may tumble within the second target  308  as a result of an increased viscosity of the second target  308 .  
     [0047] The penetrator  100  may be propelled or dispensed by any desired means. For example, as shown in FIGS. 4A and 4B, a gun  402  may be used to propel one or more of the penetrators  100 . In the illustrated embodiment, an explosive charge  404  is disposed behind the penetrator  100  within the gun  402 . Upon detonation of the explosive charge  404 , the penetrator  100  is propelled through a barrel  406  of the gun and toward a target. The penetrator  100 , however, may be propelled by any chosen means, such as by compressed air, a biasing member (e.g., a spring), or by other such methods.  
     [0048] Alternatively, as shown in FIG. 5A, the penetrator  100  may form part of a cartridge  500 . In such an embodiment, the cartridge  500  comprises a casing  502  for housing one or more penetrators  100  (only one penetrator  100  shown in FIG. 5) and an explosive charge  504 , which is disposed behind the penetrator  100 . In the illustrated embodiment, a primer  506  extends through a rear, end wall  508  of the cartridge and abuts the explosive charge  504 . A firing mechanism (not shown) of a gun  510 , shown in FIG. 5B, activates the primer  504 , which, in turn, detonates the explosive charge  504 . The propulsive energy created as a result of the detonation of the explosive charge  504  propels the penetrator  100  through a barrel  512  of the gun  510  and toward a target, as shown in FIG. 5C.  
     [0049] Further, one or more of the penetrators  100  may be dispensed by a vehicle capable of flight, such as a rocket, a missile, a bomb, or a projectile. In the embodiment illustrated in FIGS. 6A and 6B, the vehicle  602  comprises a body  604  and a means for propelling the vehicle  602 , such as an engine or a motor  606 . The penetrators  100  (only one indicated) are housed within the body  604 , as shown in FIG. 6A, until such time as they are to be deployed. A portion  608  of the body  604  is ejected from the vehicle  602  to reveal the penetrators  100 . The penetrators  100  are dispensed from the vehicle  602  as shown in FIG. 6B.  
     [0050] The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.