DETAILED DESCRIPTION OF THE INVENTION

[0020] Referring now to the drawings, simultaneous reference will be made to FIGS. 1 and 2 where one embodiment of a combination explosively formed penetrator (EFP) and fragmenting warhead in accordance with the present invention is shown and referenced generally by numeral 10 . As will be explained further below, warhead 10 is a submunition that will be separated from a delivery vehicle (e.g., projectile, missile, etc.) over a target area and then detonated to generate at least one EFP and fragments. The orientation of warhead 10 at detonation will determine the flight direction of the EFP(s) and fragments.

[0021] In the illustrated embodiment, warhead 10 has a sealed casing 12 with a wedge-based cross section. Casing 12 is filled with explosive material 14 , the choice of which is not a limitation of the present invention. Positioned in explosive material 14 are one or more initiators 16 . Positioning of initiators 16 will be discussed further below.

[0022] Casing 12 is defined by an outer radial wall 120 , an inner radial wall 121 , sidewalls 122 and 123 that separate and join radial walls 120 and 121 , and end walls 124 and 125 that define the axial ends of casing 12 . Thus, casing 12 essentially defines a geometry that is a portion of a ring that subtends an angle a that is typically 90° or less, but can be greater. In the illustrated embodiment, casing 12 is a portion of a cylindrical ring. However, other geometrical ring shapes can be used without departing from the scope of the present invention.

[0023] Casing 12 can be made from a variety of materials (e.g., metal, composites, plastics or other similar materials) and can be constructed in parts that are welded or bonded together, or can be constructed as a unitary or molded part. Regardless of construction, outer radial wall 120 is designed to form fragments after detonation of explosive material 14 . For example, as illustrated in FIG. 2 , outer radial wall 120 can have a thin inner solid wall 120 A joined to side walls 122 and 123 and in contact with explosive material 14 . Wall 120 A functions as a gas check designed to withstand a small amount of detonation pressure before vaporizing as would be understood by one of ordinary skill in the art. Attached to the exterior surface of wall 120 A are a plurality of objects 120 B that will be expelled as fragments after wall 120 A vaporizes and detonation pressure acts on objects 120 B. Each of objects 120 B is typically a solid object made of a hard material such as metal. The shape of objects 120 B can be tailored for a specific application and is not a limitation of the present invention.

[0024] Outer radial wall 120 could also be constructed as a one-piece wall scored with a predetermined fragmentation pattern. For example, FIG. 3 illustrates such a wall 120 where dashed lines 120 C represent score lines in wall 120 . Score lines 120 C define fracture lines for wall 120 after detonation of the warhead so that fragments 120 D are formed. As before, the shape of the fragments formed is not a limitation of the present invention. Accordingly, the score lines can define any regular fragmentation pattern (e.g., squares, triangles, hexagons, etc.), can define any irregular or random fragmentation pattern, or can define a combination of regular and irregular patterns.

[0025] Inner radial wall 121 forms an EFP after detonation of explosive material 14 when initiator(s) 16 lie on a radial plane (indicated by dashed lines 20 ) that bisects casing 12 . That is, radial plane 20 bisects the angle a subtended by casing 12 . While tests of the present invention have shown that warhead 10 will produce both an EFP and fragments when initiator(s) 16 are placed anywhere on radial plane 20 , performance of the generated EFP is optimized when a single initiator 16 is used and positioned immediately adjacent outer radial wall 120 and centered axially between end walls 124 and 125 . However, by providing additional initiators 16 along radial plane 20 as shown (i.e., the solid lined ones of initiators 16 lie axially between end walls 124 and 125 , and the dashed lined ones of initiators 16 lying elsewhere on radial plane 20 ), the present invention can be adapted/optimized for other scenarios such as fragmentation pattern, direction, etc. If multiple initiators 16 are provided, detonation of one or more thereof can be carried out in accordance with a predetermined/preprogrammed plan. Alternatively, warhead 10 could be equipped with a receiver/controller (not shown) coupled to each of initiators 16 . In this way, in-flight detonation of selective ones of initiations 16 could be controlled from a remote location thereby allowing the performance of warhead 10 to be optimized for a changing mission scenario.

[0026] Inner radial wall 121 can have a constant thickness as illustrated in FIG. 2 . However, it is to be understood that the geometry of inner radial wall 121 is not so limited. For example, inner radial wall 121 can be formed as illustrated in FIG. 4 where the wall's thickness is greatest along radial plane 20 , but then decreases (e.g., linearly, geometrically or in accordance with a complex function) on either side of radial plane 20 as a function of the distance therefrom. Tests of this construction have indicated that such thickness tapering of inner radial wall 121 reduces the velocity gradient experienced by wall 121 after detonation of explosive material 14 . The reduced velocity gradient helps to prevent fracturing of wall 121 (after detonation) to ensure the formation of a one-piece EFP.

[0027] As mentioned above, the present invention can be constructed to generate multiple EFPs and fragments after the detonation thereof. A warhead for accomplishing this is illustrated in perspective and cross-sectional views in FIGS. 5 and 6 , respectively, and is referenced generally by numeral 30 . Warhead 30 is similar in construction to warhead 10 with the parts that are identical not being discussed further herein. The difference between the two embodiments is that side walls 322 and 323 of warhead 30 incorporate dimpled portions 322 A and 323 A. More specifically, dimples 322 A and 323 A are concave depressions in side walls 322 and 323 , respectively, that extend convexly into explosive material 14 . After detonation of explosive material 14 , each of dimples 322 A and 323 A collapses and forms an EFP that is expelled outward from warhead 30 . While the shape of the dimples is not a limitation of the present invention, forming the dimples as portions of a sphere produces stable EFPs as is known in the art.

[0028] The wedge-based shaped warhead described herein can make up one section of an ordnance package of a plurality of such warheads. For example, when the warheads are designed as portions of a cylindrical ring as is the case with warhead 10 or warhead 30 , multiple ones thereof can be arranged to form a circular cylinder 100 as illustrated in FIG. 7 . Note that cylinder 100 could also be constructed using some combination of warheads 10 and warheads 30 . Thus, cylinder 100 comprises an adaptable, mission-responsive ordnance that can be dispersed/detonated in accordance with a predetermined plan or in accordance with a plan that is provided in real-time based on specific and changing mission requirements. Delivery of cylinder 100 and dispersement of warheads 10 can be accomplished as described in a co-pending U.S. patent application entitled “MISSION RESPONSIVE ORDNANCE” (Navy Case No. 79558), application Ser. No. ______, filed on ______, and owned by the same assignee as the present invention. The contents of this co-pending patent application is hereby incorporated by reference.

[0029] Although the present invention's wedge-based construction has been described relative to a portion of a cylindrical ring, is not so limited. Each wedge-based warhead could also be formed as a portion of a ring having a geometry other than that of a cylinder without departing from the scope of the present invention. For example, as illustrated in FIGS. 8 and 9 , each warhead could be formed as a portion of a triangular ring. More specifically, each of warheads 40 has a casing 42 defining an outer radial wall 420 , inner radial wall 421 , side walls 422 and 423 , and axial end walls 424 and 425 . The individual warheads 40 can be arranged in a triangular stack 200 . Other simple or complex geometries can be used without departing from the scope of the present invention.

[0030] The advantages of the present invention are numerous. A single warhead can produce both fragments and one or more EFPs. In this way, the same warhead can be used to defeat a variety of targets ranging from personnel to armored vehicles and structures. Speed and/or direction of both fragments and the EFPs can be controlled by in-flight adjustable features such as orientation of the warhead and selected detonation of initiators in the warhead. Thus, each warhead can be configured to be responsive to changing mission scenarios. Furthermore, the wedge-based geometry of each warhead allows multiple ones thereof to be packed in a logical stacked arrangement that can be delivered and dispersed at a target location by a mission responsive ordnance delivery vehicle.

[0031] Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.