US 3741123 A
Description (OCR text may contain errors)
United States Patent [191 Dittrich MULTI-CYLINDER SHELL OF FRAGMENTIZED METAL  Inventor: Walter H. Dittrich, Ft. Walton Beach, Fla.
 Assignee: The United States of America as represented by the Secretary of the Air Force, Washington, DC.
 Filed: July 29, 1968  Appl. No.: 749,522
 US. Cl 102/67, 102/2, 102/68, 102/DIG. 2  Int. Cl. F42b 13/48  Field of Search 102/56, 24, 24 l-lC, 102/58, 67, 68, 2, DIG. 2; 89/8  References Cited UNITED STATES PATENTS 2,774,306 12/1956 MacLeod l02/D1G. 2 2,892,407 6/1959 MacLeod 102/24 HC 2,900,905 8/1959 MacDougall 102/DIG. 2 3,000,309 9/1961 Zapf 102/67 R25,685 12/1964 Griffith et al 102/24 3,295,412 l/l967 Morley et al. 89/8 FOREIGN PATENTS OR APPLICATIONS 1,190,855 4/1965 Germany 102/DIG. 2
[ June 26, 1973 Primary Examiner-Robert F. Stahl Attorney-Harry A. Herbert, Jr. and Herbert H. Brown 57] ABSTRACT The improved shell employs two or more cylinders of metal which had been grooved in criss-cross directions and are spaced apart, and having a sheet of explosive material in between the cylinders. The innermost cylinder is filled with a high explosive which consitutes the main charge. The latter may have a square end or may be recessed to constitute a shaped charge having a metal liner. An impact detonator initiates an explosion in the sheet material which causes shock waves, some of which pass directly through the inner fragmentized cylinder and others are reflected by the outer cylinder. But all the shock waves meet at the axis of the main charge to provide a tremendous stimulus to initiate the main explosion. Thus the energy of the main explosive is increased and this energy increment causes the cylinders to break up into small fragments which spread outwardly with accelerated speed to enhance the damage potential.
3 Claims, 4 Drawing Figures MULTl-CYLINDER SHELL or FRAGMENTIZED METAL SUMMARY OF THE INVENTION The present invention relates to explosive shells which are grooved in criss-cross directions and employ a shaped charge. The general object of the invention is to increase the lethal effect of the shells without greatly increasing the cost of manufacture. The invention will be better understood when reference is made to the following description and the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 represents a vertical section of the improved form of shell but showing the detonator and primer, as well as the aft stabilizing structure in diagrammatic form;
FIG. 2 is a cross-section of the shell shown in FIG. 1 taken at aboutthe line 2-2 therein;
FIG. 3 shows a vertical section of the improved twocasing form of shell which also includes a shaped charge together with a liner. As in the case of FIG. 1, the detonator, primer and rear stabilizer are shown by way of diagram; and
FIG. 4 represents a transverse section of the modified form of shell taken along line 4 4 in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, reference characters 1, 2 and 3 represent three concentrically arranged cylinders, preferably equally spaced from one another by layers or sheets 4 of explosive material. The cylinders are constituted of grooved metal, in which the grooves (not shown) run lengthwise and cross-wise of the peripheral surface so that an explosion within, if of sufficient force, would fracture the casing at the grooves and scatter the pieces in all directions. Top and bottom elements 5, 6 of relatively thin metal extend across the cylinders and are secured thereto in any suitable and wellknown manner. The top element serves as a support for a nose cone 7 of relatively thin metal and contains the igniter device forming part of any suitable and wellknown fuse structure. The bottom element 6 may carry a stabilizing fin structure generally designated at 8 which is formed of a tail cone 9 and stabilizing fins 10 secured edgewise to an elongated cylinder 11 attached to the cone. A stabilizing structure of this type is to prevent the bomb from tumbling when released from an airplane and also to give the bomb definite direction.
The fuse and detonator apparatus 12 is shown in diagrammatic form and is supported in any suitable manner at the center of the nose cone. These fuses are generally of the impact type and are well known in the art. The fuse may include a detonator which has two active end surfaces 13, 14. The latter upon impact are caused to strike a pair of strips or ribbons l5, 16 of explosive material which are supported on blocks 17, 18 of soft, non-combustible material. A suitable material is sold on the market under the name "Styrofoam." Block 17 is preferably of rectangular form and is secured to the upper element 5 so that the strip extends alongthe upper surface of the block and then downwardly along the outer edge thereof. The edge portion of the strip extends as far as the upper surface of the outer sheet of explosive material 4 for purposes that will be explained hereinafter. The block 18 is of triangular shape, somewhat higher than block 17 and is secured at the bottom to the top element 5. Thus the strip 16 extends diagonally down from the active surface 14 of the detonator 12 to the upper edge of the outer sheet of the explosive material 4. Suitable openingsare provided in the top element 5 in order to accommodate the strips 15, 16. The interior of the inner cylinder 1 is completely filled with a high explosive of any suitable and well-known type to constitute the main charge.
When the bomb is dropped from a plane or fired from a gun the nose cone 7 impacts with the target to cause the detonator 12 to initiate a shock wave at the active surfaces 13, 14. This wave is intensified by the high explosive strips 15, 16 which carry the shock wave to the outer sheet material between the cylinders 2, 3. The detonation of the explosive sends a shock wave through the cylinder 2 which either initiates the adjacent explosive layer, i.e., between the cylinders 1, 2 directly, or indirectly, as when the shock wave reflects from the cylinder or casing 2. The process repeats itself until the main charge 19 is reached. If the 'shock wave is of sufficient intensity, the main charge is initiated directly. If the shock intensity is not sufficient, the shocks will converge on the axis of the charge, i.e. the center axis of the cylinders and the main charge 19 is exploded from the inter-action of the shock waves. When the main charge is initiated by either of these processes, the pressures and temperatures formed near the axis of the charge are considerably greater than those formed in a conventional detonation. This serves to increase the intensity of the blast against the cylinders l, 2 and 3 so that the latter are torn apart at the criss-cross grooves, and the fragments are scattered with a greatly enhanced force to increase their kill capability.
In FIG. 3, I have shown the invention in connection with a shaped charge 20 of explosive contained within a pair of concentrically arranged cylinders or casings.
The shaped charge is provided with a metal liner 21. The cylinders are constituted of metal which has been grooved in criss-cross directions as before, and there is a sheet of explosive material 22 between the cylinders. In this Figure, the elements corresponding to the elements found in FIG. 1 are given the same reference characters so as to avoid repetition.
The operation of the double-walled shell in FIG. 3 is similar to that described in connection with FIG. 1 and the same initiation of the explosion of the main charge 20 is employed. The explosion at the layer 22 by the detonator 7 causes a shock wave to occur within the space between the two cylinders or casings and these shocks either pass through the inner cylinder or are reflected inwardly by the outer cylinder depending on the strength of the shock waves. The latter converge at the center 23 of the shaped charge and their inter-action causes an extremely high power explosion to take place at the main charge. The re-entrant conically shaped recess in the main charge, together with the liner 21, adds to the intensity of the explosion by introducing a jet effect so that both cylinders would be fractured at the criss-cross grooves to force the metal pieces outwardly with high damage potential.
1. Anexplosive shell comprising a plurality of cylinders of different diameters and concentrically arranged, a metal top member extending across one end of each cylinder and in contact therewith, a metal bot- 2. An explosive shell according to claim 1 and in which the cylinders are constituted of at least three, and the pair of physically separate strips which extend from the inner end of the detonator makes contact with the explosive material between the outermost pair of the cylinders.
3. An explosive shell according to claim 1 and in which the top member is provided with openings through which said strips extend.
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