High Velocity Flight Stabilized Fragmentation Device

Abstract

There is disclosed an explosive controlled fragmentation device for obtaig high velocity attitude controlled projection of a plurality of darts. This is accomplished by controlling the thickness of the explosive adjacent the darts so as to obtain the impulse necessary to turn the darts into a blunt-end forward flight attitude.

Description

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to ordnance equipment, and more particularly to an explosive fragmentation device wherein the attitude of the projected fragmentation material may be controlled.

Those concerned with the development of fragmentation explosive devices such as anti-aircraft missile and projectile warheads, drop bomb warheads, land mines, etc., have long recognized the need for controlling the pattern, velocity and attitude of the fragmentation material projected therefrom since the lethality of such controlled fragmentation material has been found to greatly exceed that of the conventional, randomly projected, fragmentation devices. In a conventional explosive, the fragmentation or shrapnel pieces are of irregular shape and are projected in a random manner. Although such conventional devices have served the purpose, they have not proven entirely satisfactory under all conditions of use. On the other hand, if the fragmentation or shrapnel pieces are of aerodynamically stable design and are projected in a predetermined pattern, the effective "kill" ability thereof may be greatly enhanced.

The general purpose of this invention, therefore, is to provide an explosive fragmentation device which embraces all of the advantages of similarly employed conventional explosive devices and possesses none of the aforedescribed disadvantages. To attain this, the present invention utilizes a specifically configured fragmentation material in conjunction with a specifically designed explosive charge.

Accordingly, an object of the present invention is to provide an explosive device which, upon detonation, forms a predetermined fragmentation pattern of high velocity.

Another object is to provide a method of forming an explosive fragmentation device in which the attitude and velocity of the projected fragmentation or shrapnel pieces may be controlled.

A further object of the invention is the provision of an explosive fragmentation device wherein the attitude of the projected fragments may be controlled so as to maximize the depth that the fragments penetrate a target.

Still another object is to control the fragmentation acceleration and flight attitude of an explosive device through precise local control of the detonation process.

A still further object is to provide an explosive fragmentation device which is characterized by simplicity of construction, low cost, and ease of operation and use.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which:

FIG. 1 is an elevation view, partly in section, of a preferred embodiment of the invention;

FIG. 2 is an end view of the device taken on the lines 2 -- 2 of FIG. 1 looking in the direction of the arrows; and

FIG. 3 is a side view taken on the lines 3 -- 3 of FIG. 1 looking in the direction of the arrows.

Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1, which illustrates a preferred embodiment of the invention, an explosive fragmentation device generally indicated by reference character 10 comprised of an annular explosive charge 12 having a plurality of double wedge dart-shaped fragmentation pieces 14 secured around the cylindrical periphery thereof. A pair of flat end pieces 16 and a central hub 18, which may house a detonator, complete the assembly and form a generally cylindrical explosive device. The darts 14 may be secured to the explosive charge 12 by any conventional means, such as an epoxy cement or a snap ring secured to end pieces 16 and folded over the tapered tail end of the darts 14.

The high explosive charge 12 is adjusted in thickness so as to provide precise control of the attitude and velocity of the projected darts 14. In the illustrated embodiment, the explosive charge 12 has a maximum thickness at the longitudinal center of the cylinder adjacent the blunt ends 15 of the darts 14 and tapers to a minimum thickness adjacent the tail ends 17 of the darts 14. Therefore, the thickness of the charge 12 is controlled so as to attain the impulse distribution necessary to turn the darts into a blunt end forward attitude when projected. The flight of the darts as they are projected from the explosive device 10 is illustrated by reference characters 14', 14", 14'", and 14"". In other words, as the explosive charge 12 is detonated, the impulse generated is greatest adjacent the thickest portions thereof. Accordingly, the blunt ends 15 of the darts 14 situated adjacent the thickest portion of the charge 12 will be projected with slightly greater force than the tail ends 17 of said darts. Therefore, as the darts are projected from the charge 12, they are caused to turn about their axes into a blunt end forward attitude so as to fly stabily in radial trajectories about the cylindrical axis of the charge 12. The darts 14 will, therefore, strike end-on thereby maximizing penetration by maximizing the momentum per unit contact area. The exact control of flight for a particular configuration and attitude is obtained through proper distribution of explosive thickness and dart mass.

As best illustrated in FIGS. 2 and 3, the darts 14 are packed on their edges adjacent one another so as to provide close packing and mutual support during the initial high pressure phase of the detonation, thereby preventing permanent deformation or break-up of the darts. In addition to the precise distribution of explosive thickness to dart mass, the initial flight of the darts 14 through the high velocity detonation products assists in reducing the high angular velocity necessary to turn the darts in the short time available, thereby reducing over-shoot and possible tumbling.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. For example, the basic idea is adaptable to a wide variety of sizes, ranging from bomblets to large warheads. Pattern size or angle of divergence of the trajectories shown in FIG. 1 may also be achieved through the use of barrel or spool-shaped explosive charges or by control of the explosive thickness in the cylindrical shape. Sizes and materials of the darts 14 may be selected to suit the intended targets while multi-point timed initiation may be used to control wave shapes and impulse distribution. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

Claims

What is claimed is:

1. An explosive fragmentation device comprising

a uniformly tapered explosive charge having a generally cylindrical configuration with a maximum thickness adjacent the longitudinal center thereof;

a plurality of fragmentation pieces disposed adjacent said charge, said pieces having a varying thickness in cross-section, said pieces being arranged such that the thickest portion thereof is disposed adjacent to the substantially thickest portion of said charge;

said fragmentation pieces being dart-shaped and closely packed together with their thick ends adjacent the longitudinal center of said explosive charge and whereby upon detonation of said charge, said pieces are caused to turn into a thick end forward flight attitude.

2. An explosive fragmentation device in accordance with claim 1 wherein:

said explosive charge tapers uniformly to a minimum thickness adjacent the ends thereof; and

said dart-shaped pieces taper uniformly to a minimum thickness at their tail ends adjacent the ends of said charge.

3. An explosive fragmentation device in accordance with claim 2 wherein:

said dart-shaped pieces are disposed in pairs around the periphery of said explosive charge with the thick end of one of the darts in a pair being adjacent the thick end of the other of the darts in a pair.