Patent Application
20090078147
The present invention relates to a method of initiating at least one first external explosive charge by means of a kinetic impulse which is transferred to the said first external explosive charge by splinter bodies, directed towards this first external explosive charge and flying freely at high speed, which have separated from a second explosive-filled action element A, initiated on own initiative and provided with an outer shell which surrounds the explosive and, upon detonation thereof, forms splinters.
The invention also relates to an explosive-charged action element A, provided with a splinter-forming outer shell, intended to release, upon detonation of its own explosive charge, splinter bodies flying freely at high speed and intended to be used, according to the method according to the invention, to initiate at least one external explosive charge by transferring a sufficient quantity of kinetic impulse to the said external explosive charge to initiate the same to detonation.
The invention further relates to a splinter body tailored to the implementation of the said method of initiating external explosive charges and forming part of the herein utilized splinter shell.
The invention is especially suitable for combating an incoming explosive-charged enemy missile or some other unit which can be combated by means of splinter bodies configured according to the invention, such as, for example, artillery shells, dropped bombs or aircraft, watercraft or land craft, etc., which can be initiated with the specified invention, the explosive of the combatable unit being initiated to immediate detonation by means of splinter bodies directed towards this explosive at high speed by an external explosion.
It has previously been known that explosives can be initiated to denotation by the kinetic impulse from large splinters which hit the explosive at high speed. This knowledge has been utilized, inter alia, in the design of missiles intended to combat enemy explosive-charged missiles incoming towards one's own territory. It will then, in fact, be sufficient for an own anti-missile second missile to enter into the vicinity of the first enemy incoming missile(s) in order for the own second missile to be able to eliminate the incoming first missile(s) with splinter bodies, which are formed or released and are directed at high speed towards the incoming first missile upon detonation of an explosive-charged action element forming part of the own second missile and provided with a splinter-forming shell.
The drawback with this approach has previously been that large splinters which hit the explosive charge of the incoming missile at high speed have been needed to ensure that this would be initiated to detonation. This gave rise to the need to provide the own anti-missile second missile with a large action element comprising a thick splinter-forming outer shell and a powerful explosive charge fragmenting the splinter shell, which automatically meant that the weapon system as a whole became large and expensive. One example of an American weapon system of this kind is the so-called Patriot robot.
The main object of the present invention is to achieve an improved method of initiating a first external explosive charge, an improved explosive-filled action element for implementation of the said method, and a splinter body tailored to the implementation of the said method, which initiation method, action element and splinter body substantially reduce, preferably eliminate, the abovementioned problems, the initiation method, the favourable effects of the action element and of the splinter body being able to be better utilized than previously.
A further object of the present invention is to achieve a method of making it possible to markedly reduce the size of the action elements forming part of such anti-missile missiles without thereby reducing the capacity of the action elements to initiate the explosive charges in such incoming missiles at which the anti-missile missiles might be fired.
The said objects, and other aims which have not here been enumerated, are satisfactorily met by way of that which is defined in the present independent patent claims. Embodiments of the invention are defined in the independent patent claims.
Thus, according to the present invention, an improved method has been achieved of initiating at least a first external explosive charge by means of a kinetic impulse, which method is characterized in that the splinter bodies released from the outer shell of the action element, upon detonation of the explosive charge forming part of the action element, have forcibly been given a shape having a large broadside in relation to their own mass, and in that these splinter bodies are accelerated evenly towards the said first explosive charge so that these splinter bodies will hit the said first explosive charge with their own broadside first and, in so doing, will supply a sufficiently high kinetic impulse to the first explosive charge over a sufficient area to initiate the particular explosive charge to detonation.
According to further aspects of the method according to the invention, it is the case:
that the division of the splinter shell of the action element into splinter bodies having a large broadside in relation to their own mass is ensured by the splinter shell being given different strength in its various parts, either by means of weak links in or by means of reinforcing counterstays against those parts of the splinter shell along which a division of the same gives the splinter bodies released from the splinter shell the desired shape;
that the said even acceleration of splinter bodies having a certain extent in the detonation direction of the explosive which accelerates the splinter bodies upon detonation is achieved by a retardation of the acceleration of the splinter bodies along that one of the edges (a) of the splinter bodies which will first be hit by a detonation wave from the detonating explosive, which retardation is tailored such that the detonation wave has time to reach the second edge (b) of the splinter body, which is not retarded in the same way, whereby the splinter body will be accelerated evenly away from the detonating explosive charge;
that the said even acceleration of splinter bodies having a certain extent in the detonation direction of the explosive which accelerates the splinter bodies upon detonation is achieved by the splinter bodies having been pre-given, by bevelling, a smaller thickness (t13) along the edge which is last hit by the detonation wave from the detonating explosive.
Furthermore, for the implementation of the methods according to the invention, the tailored splinter body (5) forming part of the herein utilized splinter shell (7) is characterized:
in that the splinter body has a broadside whose extent in the lateral direction substantially exceeds the thickness of the splinter body, and in that the said broadside, preferably, has the shape of a more or less flat circular, elliptical, rectangular or polygonal surface, alternatively in that the splinter body has the shape of a relatively flat or flattened ellipsoid, rounded or polygonal lamina, plate or disc.
Further, according to the invention, the explosive-charged action element is characterized:
in that the said splinter bodies have been pre-guaranteed a configuration each having a large broadside facing in the acceleration direction of the splinter bodies.
According to further aspects of the explosive-charged action element, it is the case according to the invention:
that the splinter bodies forming part of its original shell, which forms splinters upon detonation of the explosive, have the shape of polygonal, rounded or oval plates, laminae or ellipsoids;
that its shell, which forms splinters upon detonation of the explosive, is produced by powder-metallurgical methods comprising splinter bodies inserted in a matrix produced by sintering of a metallic powder material and each having a large broadside relative to the own mass of the respective splinter body and having a higher intrinsic strength than the matrix;
that the powder-metallurgically produced matrix of the splinter-forming shell, in which the splinter bodies are inserted, is configured such that it covers with a sufficient quantity of sintered powder material that part (a) of the respective splinter body which will first be reached by the detonation wave from the explosive charge detonating the action element that the acceleration of this first part (a) away from the detonation point is delayed for a sufficient period of time to allow it (a) to be accelerated away from the detonation parallel with that part (b) of the same splinter body which is last reached by the same detonation wave and which is not correspondingly retarded, i.e. is unretarded in relation to the first part (a);
that that part (b) of the same splinter body which is last reached by the same detonation wave is covered with a smaller quantity of sintered powder material than that part (a) of the respective splinter body which will first be reached by the detonation wave from the detonating explosive charge of the action element;
that it further comprises counterstays, disposed on the outside of the splinter shell and having such a thickness (t12, t13) and extent that the acceleration of the splinter bodies forming part of the splinter-forming shell of the explosive charge away from the detonation is retarded along the edges (a) which are first touched by the detonation wave formed upon detonation of the explosive for a sufficient period of time to allow the splinter bodies to be accelerated evenly away from the detonation;
that the individual splinter bodies are configured like disc plates bevelled along the edge (b) last hit by the detonation wave, such that the acceleration of the splinter bodies forming part of the splinter-forming shell of the explosive charge away from the detonation is retarded, in relation to the acceleration of the bevelled edge (b), along the edges (a) which are first touched by the detonation wave formed upon detonation of the explosive, for a sufficient period of time to allow the splinter bodies to be accelerated evenly away from the detonation;
that the shell which surrounds the explosive and forms splinters upon detonation of the explosive, on its inner side facing towards the explosive, has been provided with at least one shock wave trap, in the form of at least one shock-wave-influencing material lining, with a view to guaranteeing a predetermined division of the splinter shell into splinter bodies of the desired size and shape;
that it comprises a detonator for initiating the explosive charge forming part thereof, this detonator, which is disposed at one end of the explosive charge, having been combined with a wave shaper;
that it comprises multi-initiation detonators having a plurality of initiation sites, disposed along the outer face of the explosive charge, for instantaneous initiation of the explosive charge.
The basic concept behind the present invention is thus to configure the components forming part of the own action element so that the splinter bodies shaped by the splinter shell of the own action element acquires, compared with their own mass, a large surface facing in the direction of an incoming enemy missile, shell, bomb, craft, etc. and a correspondingly small thickness in the same direction, which means that that side of the splinter bodies, hereinafter referred to as the broadside, which is directed towards and hits the incoming enemy missile, etc., comprising the above and below named first external explosive charge, shall have the shape of laminae, plates, discs, ellipsoids or equivalent. The invention further includes an assurance that these splinters of laminar, plate-like, ellipsoid or other equivalent configuration shall hit the intended target at a sufficiently high speed with their own broadside first and, in so doing, transfer a sufficient kinetic impulse to the explosive charge of the first incoming enemy missile over a sufficient area to initiate the explosive to detonation. This specific configuration of the splinter bodies thus offers a possibility of hitting the target with splinter bodies which, in the event of a hit, provided that they have thus initially been given a sufficiently high speed and despite their limited own mass, transfer a sufficient quantity of kinetic impulse over a sufficient area of explosive to ensure an initiation of the explosive charge forming part of the combated missile. By impulse is here meant, in somewhat simplified terms, a change in the momentum, i.e. the product of mass times speed in a certain direction, of an object.
Since the above-indicated shape of the splinter bodies configured according to the invention has been able to be given a large surface compared with their own mass, the splinter-forming shell of the action element has been able to be made thinner and hence lighter, whilst, at the same time, a correspondingly lesser amount of detonating charge of explosive inside the splinter-forming shell will be needed to give the splinter bodies released therefrom upon detonation of the explosive charge a sufficiently high initial speed in the direction of the target, i.e. of the foreign missile. This general basic notion thus offers the prospect of markedly reducing the size of the action element which is necessary to combat foreign incoming explosive-charged missiles, and hence the size of the entire weapon system in question and the costs of the same.
In order for the laminar, plate-shaped or ellipsoidal, etc. splinters to produce the effect outlined above, it is required, however, that, firstly, they maintain their original shape until hitting the target and, secondly, they actually hit the target with their broadside first.
The first of the above-specified conditions means that the splinter shell from which the splinters are released, upon detonation of the explosive charge disposed inside the splinter shell, is fragmented only at precisely those points and along those parting lines which were originally presumed, and this can be ensured by means of weaker sections, for example in the form of material thinnings, at the said points and along the desired parting lines, built from the outset into the splinter shell. A better solution to the same problem is, however, to produce the splinter shell by powder metallurgy methods, pre-produced splinter bodies being inserted into a matrix, produced by powder-metallurgy methods, which separates the splinter bodies one from another and from the explosive charge and which, by virtue of the fact that the matrix, upon detonation of the explosive, surrounds the splinter bodies, gives these a gentle acceleration, which prevents the splinter bodies from fragmenting and ensures that these are accelerated in the desired direction, namely in the direction of the incoming enemy missile, etc. This process for the production of the splinter shells therefore has the advantage that, by producing the splinter bodies separately, it is possible to give them the most favourable configuration for each individual case and, moreover, to give them a substantially higher strength than the matrix material which initially holds the splinter shell together. Consequently, it is thus possible effectively to prevent an undesirable fragmentation of the splinter bodies and to ensure that these, when they are released from the splinter shell and begin their flight towards the target, acquire precisely that configuration which is designed for the purpose.
The division of the splinter shell into splinter bodies of a desired shape, irrespective of whether the splinter shell is produced by powder-metallurgical methods or not, might also be to some extent ensured by specific counterstaying elements disposed on the outside of the splinter shell along desired rupture lines between the desired splinter bodies.
In order to reinforce and further ensure the division of the splinter shell into splinter bodies of desired size and shape along predetermined rupture lines or along the space between prefabricated splinter bodies baked into a powder-metallurgical matrix, and in order, at the same time, to prevent an undesirable further fragmentation of the splinter bodies, the inner side of the splinter shell can be provided with shock wave traps in the form of one or more layers of linings of material which exhibits strongly different acoustic properties from the rest of the splinter shell. As examples of materials which can be used as such shock wave traps, plastics of different hardness and density can be cited.
The above-specified other conditions for the splinter shell configured according to the invention, giving the desired effect in the form of a detonation of the explosive charge in a foreign missile or in another target comprising an explosive charge, for example an artillery shell, bomb, etc. according to the above, namely that the splinter bodies according to the invention shall hit the target with their own broadside first, mean that the splinter bodies, upon detonation of their own explosive charge and their associated own release from the splinter-forming shell or the matrix, must be accelerated evenly towards the target without any form of simultaneous rotary motion.
Initially, this means that all splinter bodies must be given constant and uniform acceleration conditions, which, when the explosive charge is initiated from its one end, can be relatively easily arranged by means of a wave shaper which is installed in the initiation end and compensates for the gradual changing, by the detonation wave formed in the spot initiation, of the radius of curvature of its own detonation wave during its propagation through the explosive charge from its initiation end to its other, opposite end.
A dearer and more complex solution to the same problem is to provide the charge with a detonator for multi-initiation, which, along its own outer face, gives an instantaneous initiation over the whole of the circumference (envelope surface) of the charge.
The even acceleration which is sought for the method according to the invention further means that the splinter bodies, as already indicated, are prevented from being given any form of rotated motion in connection with their release from the splinter shell surrounding the explosive, by the detonation of the latter, and their acceleration towards the target. For the splinter bodies according to the invention, it is important, as pointed out previously, that these should each have at least one large surface compared with their own volume and that they should hit the target with this own broadside first. The own surface requirement can be met by each splinter body having a certain extent in the longitudinal direction of the original splinter shell. This means, in turn, that one edge/side of each specific splinter body will be hit by the detonation wave from the detonating own explosive before its opposite edge side, which in turn, if no special measure were taken, would automatically result in the splinter, upon detonation of its own explosive, having been given a rotary motion about an axis midway between the said edge sides.
According to one development of the invention, it has proved possible to ensure the even acceleration of the splinter bodies, however, with the aid of well-dimensioned counterstays placed on the outer side of the original splinter shell. These counterstays, which can form part of the original splinter shell matrix in the form of a sectionally arranged, increased material thickness towards the outer side of the splinter shell, or alternatively as separate counterstays disposed on the outer side of the splinter shell. These counterstays thus have the function of offering exactly the right resistance when the detonation wave first reaches the first one edge side of the respective splinter body and, at the same time, of preventing the first hit edge/side of the splinter body from managing to be accelerated away from the detonation front before the detonation wave reaches the opposite edge side of the same splinter body.
Through the use of counterstays of the above-specified type, it has thus proved possible to resist, i.e. retard, the acceleration of that edge/side of the respective splinter body which has first been reached by the detonation wave until the detonation wave reaches the opposite edge side of the splinter body, the result being that the splinter body is accelerated evenly away from the detonating explosive. In a splinter shell produced by powder-metallurgical methods, such counterstays, for example, could be formed by machine-cutting out of the splinter shell matrix produced by powder-metallurgical methods. Another method used for the same purpose would be to configure the individual splinters as disc plates bevelled along the edge which is last hit by the detonation wave.
The invention has been defined in the subsequent patent claims and it shall now be described somewhat more closely in connection with the appended figures.
Further advantages and effects will emerge in the course of study and consideration of the following detailed description of the invention, including a number of its advantageous embodiments, the patent claims and the accompanying drawing figures.
With reference to the appended figures,
The action element A, illustrated in
As has already been pointed out, the splinter bodies 5 shall be accelerated evenly towards the incoming missile 2, so that the splinter bodies 5 hit the first, i.e. incoming missile 2 with their broadside 5′ first. A method of achieving this effect is more closely illustrated in
From
In order to avoid this undesirable effect, the matrix, see further below, which constitutes the coherent portion of the splinter shell 7 and in which the splinter bodies 5 are baked in, has been given counterstays 12 and 13 of different thickness t12 and t13 level with the edges a and b respectively of the splinter body 5, see
The type of splinter shell 7 which is shown in
The saw-toothed profile, shown in
The invention is not limited to the illustrated embodiment, but can be varied in a variety of ways within the scope of the patent claims. It will be appreciated, for example, that the enemy target which is specifically described herein, i.e. the incoming missile 2 which is specified above in the illustrative embodiment can also be comprised by any other aerial, water or land target comprising an explosive which can be initiated according to the patent claims, for example a shell fired by means of a suitable barrelled weapon. In the same way, the own missile 3 may also be constituted by a barrelled projectile.
It will further be appreciated that, as previously indicated, the saw-toothed profile can be replaced by, for example, a bevel along the edge of the splinter body which is last hit by the detonation wave.
It will be appreciated that the number, the size, the material, the characteristics and the shape of the elements and components forming part of the action element A, for example the splinter bodies, the wave shaper, the shock wave traps, etc., are tailored to other incorporated elements or components and the enemy target(s) which the action element is intended to combat.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0600063-2 | Jan 2006 | SE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/SE2006/001481 | 12/22/2006 | WO | 00 | 11/18/2008 |
