FR2651569A1 - SET OF TANDEM PROJECTILES. - Google Patents

Abstract

The assembly comprises two projectile bodies (14, 16), arranged axially one behind the other, in a common propulsion cage and which bear on one another in the contact region between them . The two projectile bodies (14, 16) are assembled together, by shape matching, the shape matching assembly (20) being removed after leaving the muzzle of the gun barrel, under the effect of the forces d air flow acting on the fins (22) of the tail of the two projectile bodies.

Description

! 2651569

TANDEM PROJECTILES SET

  The present invention relates to a set of tandem projectiles comprising two projectile bodies, arranged axially one behind the other in a common propulsion cage and which bear on one another

  in the contact region lying between them.

  A set of projectiles of this type is known, for example from document DE-A 32 07 220, in which two kinetic effect projectiles, sub-calibrated, stabilized by fins, are mounted in a common propulsion cage. In this case, the rear of the front kinetic effect projectile and the top of the rear kinetic effect projectile are in bearing contact with one another, by plane surfaces of corresponding shape,

  for the moment of shooting acceleration.

  These sets of projectiles are intended to combat armor provided with active explosive modules. In this case, the first projectile triggers the active module, so that the next projectile, serving as the main penetrator, can pierce the targeted shielding without problem. To obtain an optimal effect, the two kinetic effect projectiles must hit the same

  point of impact, at a defined distance from each other.

  The distance between the projectiles and. kinetic effect is obtained by what is known as "aerodynamic coupling", that is to say by different aerodynamic characteristics or by acting on the respective coefficient of air resistance c, or also by appropriate geometry (dimensions,

  chamfering, etc.) of the tail fins.

  It is thus possible to preselect an optimal adjustment of the distance between the kinetic effect projectiles, but always only for a limited range of distance from the objective. During the passage through the tube, the front projectile body can only be slightly supported by the next projectile body, so that the centering and largely also the support, must be done

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  by the propulsion cage. This requires a propulsion cage of appropriate size and length; it is then very heavy and hinders the detachment operation

projectile bodies.

  It is further considered as a disadvantage that the front projectile body begins to move away considerably from the rear projectile body, when it passes through the mouth and when the segments of the propulsion cage begin to open at the front, and it does not resume the optimal distance until after the fact. If the distance between the projectiles is too great, the effect of aerodynamic coupling is reduced; the top of the next projectile remains in the flow channel or 'downwind' of the

first projectile.

  The present invention proposes to indicate a set of tandem projectiles of the aforementioned type which guarantees a good centering and support of the front projectile, during the crossing of the tube and which allows a separation and a progressive separation of two projectiles, during their flight, to reach an optimal distance given to the

moment of impact on the target.

  This object is achieved according to the invention in that the two projectile bodies are assembled together, by shape match, the shape match assembly being removable after leaving the muzzle of the barrel, under the effect of air flow forces. Due to the fact that the two projectile bodies are first assembled to each other by concordance of shape, a good centering and support of the front projectile body is guaranteed, during the acceleration of fire. Since the assembly by concordance of shape is eliminated only after the exit of the muzzle of the weapon tube, under 1 effect of aerodynamic forces, the two projectile bodies do not deviate too much 1 ' on the other, even after the segments of the propulsion cage have been detached. Their separation is done continuously and slowly, so that one can fully

  exploit the advantages of aerodynamic coupling.

  In a variant of the invention, provision is made on the tail fins of the front projectile body and of the

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  rear projectile body, means capable of causing air flow forces of different intensity to act, so that the shape-matching assembly can be suppressed by the difference in the rotational torques exerted by the fins d empennage. In another variant of the invention it is provided that the two sets of projectiles have a common screw connection, in the contact region; the tail fins of the front projectile body and the rear projectile body are chamfered in opposite directions, and the orientation of the screw connection or of the thread, between the two projectile bodies, is such that the torques acting on the tail fins on which the air flow arrives,

remove the screw connection.

  In another variant of the invention it is provided that the tail fins of the rear projectile body are chamfered so that the rear projectile body rotates to the right and the tail fins of the front projectile body are chamfered the front projectile body turns to the left,

  the screwed assembly having a left pitch thread.

  In another corresponding variant of the invention, it is provided that the tail fins of the rear projectile body are chamfered so that the rear projectile body turns to the left and the tail fins of the front projectile body are chamfered so that the front projectile body rotates to the right, the screw assembly having a

straight pitch thread.

  Thanks to these embodiments which have just been mentioned, a relatively rapid elimination of the assembly is obtained by concordance of shape or a

  separation of the two projectile bodies.

  If you want the two projectile bodies to separate from each other only after a certain distance in flight or that the detachment of the two projectile bodies from each other takes place more slowly, it is interesting to predict that the tail fins of the

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  two projectile bodies are chamfered in the same direction and the screw connection is eliminated simply because of the difference between the torques generated by

the tail fins.

  To prevent the two projectile bodies from moving away from each other over an optimal distance, an additional mechanical coupling is expediently provided, between the two projectile bodies, under the

  shaped like a thin wire rope.

  Examples of embodiments of the invention are described below in more detail with reference to the appended drawings, in which: FIG. 1 represents a set of known tandem projectiles, FIG. 2 represents an assembly by concordance of shape according to the invention of two projectile bodies arranged one behind the other, FIGS. 3 and 4 respectively represent a variant of the shape matching assembly according to the invention of two projectile bodies arranged

axially one behind the other.

  In FIG. 1, the reference 10 designates a set of known tandem projectiles. It consists of a rear projectile body 16 of large mass and a front projectile body 14, of lower mass, arranged axially in front, both being surrounded by a propulsion cage 12 in one piece, common. In order to transmit the acceleration forces from the propulsion cage to the projectile bodies, the usual means of assembly by concordance of shape, not shown, are provided, such as annular grooves or threads. The front projectile body 14 is supported, at the rear, in a flat contact region 18, on the flat top of the rear projectile body 16. The two projectile bodies 14, 16 are sub-calibrated projectiles and present to the rear, tail fins 22 and 24 suitable for stabilization in flight. FIG. 2 represents, in an enlarged view, the front projectile body 14 and

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  only the region of the top of the rear projectile body 16. According to the invention, provision has been made for a concordance assembly of centering form, in the contact region of the two projectiles. To this end, the rear projectile body 16, of larger diameter, has at

  its apex, obviously or drilling 34 with thread 36.

  The front projectile body 14, of smaller diameter,

  has, at the rear, a threaded rod 30 with on it

  ci a thread 32. The two projectile bodies 14 and 16 are assembled together, by the screwed assembly 26, so that the rotational torques exerted on the tail fins 22 and 24 on which the

  draft, remove the screw connection 26.

  FIG. 3 represents another variant according to the invention of the screwed assembly 26, between the two projectile bodies 14 and 16. In this case, the front projectile body 16 has, at the rear, a bore 38 with internal thread 40 f the top 46 of the rear projectile body 16 is of reduced diameter and has a corresponding thread 44, in the assembly region. The extended top 46 of the projectile is cylindrical over a certain part of its length and is in contact with the internal surface of the bore 38, so that it also provides centering and that the screw connection 26 is therefore less

soil 1 icity.

  Figure 4 shows the assembly of the two projectile bodies, by an additional mechanical coupling, in the form of a wire rope 48. To accommodate the wire rope 48 wound or wound in one recess 38 rear of the body of front projectile 14, the top 46 of the rear projectile body 16 has an even smaller diameter at the tip and in the form of a coil mandrel 50. The ends of the metal cable 48 are fixed in the center or in the middle of the front projectile body 14 and at the top 46 or on the reel mandrel 50 of the rear projectile body 16. In the initial state, the metallic cable is wound in the form of a reel 52 around the reel mandrel 50. After launch of the projectile set, the body of

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  front projectile 14 can move away from the rear projectile body 16 only over a maximum distance which depends on the length of the metal cable 48, With the construction according to the invention of a removable assembly by concordance of shape, a stable guide is obtained, a support and centering of the two projectile bodies during the passage through the tube; the elimination of the assembly by concordance of shape after leaving the mouth of the tube, allows the two projectile bodies to move away from each other, slowly and continuously,

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Claims (9)

  gEv..gN .: .... c ....... 1. Set of tandem projectiles (10) comprising two projectile bodies (14, 16), arranged axially one behind the other, in a propulsion cage (12) common and which bear one against one another in the contact region (18) lying between them, characterized in that the two projectile bodies (14, 16) are assembled together, by shape matching, the shape matching assembly (20) being removed after leaving the mouth of the   weapon barrel, under the effect of air flow forces.   2. Projectile assembly according to claim 1, characterized in that on the tail fins (22, 24) of the front projectile body (14) and of the rear projectile body (16), means capable of acting air flow forces of different intensity, so that the shape matching assembly (20) can be suppressed by the difference in the rotational torques exerted by the tail fins (22, 24).   3. Set of projectiles according to claim 2 or 3, characterized in that: - the two sets of projectiles (14, 16) have a common screw connection (26), in the contact region (18), - the fins d the tail (22, 24) of the front projectile body (14) and of the rear projectile body (16) are chamfered in opposite directions and, - the orientation of the screw assembly (26) or of the thread, between the two projectile bodies (14, 16), is such that the torques exerted on the tail fins (22, 24) on which the   draft, remove the screw connection (26).   4. Projectile assembly according to claim 1, 2 or 3, characterized in that the front projectile body (14) has, at 1 rear, a threaded rod (30) with a thread (32) and in that the projectile body 8 2651569   rear (16) has, at its top, a recess (34) (drilling) with internal thread (36).   5. Projectile assembly according to claim 1, 2 or 3, characterized in that the front projectile body (14) has, at the rear, a recess (38) (pergage) with internal thread (40) and in that the rear projectile body (16) has, at its top, a rod threaded (42) with thread (44).   6. Set of projectiles according to one of the   Claims 1 to 5, characterized in that the fins   tail (24) of the rear projectile body (16) are chamfered so that the rear projectile body (16) turns to the right and the tail fins (22) of the front projectile body (14) are chamfered so that the front projectile body (14) turns to the left, the screw assembly (26) having a thread not left.   7. Set of projectiles according to one of   Claims 1 to 5, characterized in that the fins   tail (24) of the rear projectile body (16) are chamfered so that the rear projectile body (16) turns to the left and the tail fins of the front projectile body (14) are chamfered so that the front projectile body (14) turns to the right, the screw assembly (26) having a thread of not right.   8. Set of projectiles according to claim 1, 2, 3, 4 or 5, characterized in that the tail fins (22, 24) of the two projectile bodies (14, 16) are chamfered in the same direction and in that the screw connection (26) is eliminated simply because of the difference between the torques generated by the tail fins (22, 24).   9, Set of projectiles according to one of   Claims 1 to 8, characterized in that the two bodies   projectile (14, 16) have a mechanical coupling, for example in the form of a metal wire (48)