FR2759453A1 - SUB-CALIBER PROPULSION CAGE PROJECTILE - Google Patents

Abstract

The invention relates to a sub-calibrated propulsion cage projectile with a tungsten core and a plastic tip, as well as a feed cover with internal breaking points, connected to a propulsion cage (5). made of light metal, the supply cover (3) being formed at the rear as a guide strip (4), with a view to producing a rotation. The entire projectile having a throttle groove (8) for assembly with a case. A separate, elastic sealing disc (11) is provided below the propulsion cage (5), which guarantees a secure seal during passage through the tube. A zone of the supply cover (3), plastically deformable under the effect of heat, forms with peripheral grooves (9) of the propulsion cage (5), after cooling, a fixed assembly, not susceptible to rotation and without deformation.

Description

Projectile with ... undersized propulsion cage

  The invention relates to a sub-projectile

  calibrated, with propulsion cage, with a core made of a material of high density with a point as well as with a supply hood, having internal breaking points, which is connected by correspondence of shape with a propulsion cage made of light metal, the supply hood being shaped at the rear in a guide strip, for the production of a rotation, and the whole of the propulsion cage projectile having a throttling groove for assembly with a propellant charge socket. By patent US-3,446,147, a sub-calibrated projectile with propulsion cage, stabilized in rotation, of this type is known, the core of which is made of tungsten carbide and on the front face of which an aluminum tip is fixed by a cone outside. The nucleus and the point of the projectile are surrounded by a one-piece supply hood, which is assembled at the rear, by shape correspondence, with a propulsion cage, by means of a thread, a shoulder of the projectile core being stopped axially, in the case of assembly by concordance of shape of the propulsion cage with the cover

  intake, by a radial appendage of the intake hood.

  A rear area, of slightly larger diameter, of the outer envelope of the supply hood, is shaped as a guide strip. During the passage through the weapon tube, the transmission of the rotation, from the guide strip of the supply hood to the propulsion cage, is effected by means of the thread between the propulsion cage and the hood feed, a deformation of the thread taking place under the effect of the rotation and the gases of the propellant charge can be disadvantageously blown between the propulsion cage and the feed hood, which can give rise to premature destruction of the supply hood,

  already during the passage through the weapon tube.

  In a still disadvantageous manner, an annular peripheral groove is provided on the propulsion cage, in which the propellant charge socket is fixed, which means that when the ammunition is brought into the fired chamber, the threaded area described above in the supply hood can be so heavily stressed that a

  thread shearing is possible.

  The rear shoulder on the indenter core also forms increased air resistance due to the larger diameter, which results in considerable loss of speed during flight and cannot be obtained. in the target that a

reduced perforation power.

  Still disadvantageously, with an aluminum projectile point, in the case of multi-plate targets, one can only obtain a reduced perforation power, because the aluminum point remains too long fixed on the core of the indenter, after the impact on the target, and this results in disadvantageous oscillations when crossing the target. In the case of the use of this projectile in a Gatling type weapon, there is furthermore no indication given to a person skilled in the art as to how, in the case of tubes heated by shooting, cartridges still remaining in the chambers at the end of a firing, can be detected for

their ejection.

  The object of the invention is to produce a projectile with a propulsion cage of the same type, which, with simple manufacture, makes it possible to avoid the cited problems relating to sealing, resistance to supply and firing, loss of speed as well as the loss of the perforation power in the case of multi-plate targets, and allows adjustment of the projectiles in

the case of hot gun tubes.

  This object is achieved according to the invention in that: a) the propulsion cage contains, for the assembly of the supply hood, peripheral grooves and the supply hood contains a bore, which, in this zone, is plastically deformed for the production of the assembly under the action of heat, and which, after cooling, fixedly surrounds the grooves, by agreement of shape; b) below the propulsion cage is placed an elastic sealing disc of plastic material, which has a sealing lip oriented towards the rear; c) the point of the projectile is made of plastic reinforced with glass fibers; d) on the outside of the supply hood is placed a metal strip, closed around the periphery, for detecting the projectile; e) the throttle groove is located on the rear side of the supply hood, for fixing the

propellant charge socket.

  The assembly by concordance of shape according to the invention of the propulsion cage with the supply hood can be carried out in a very simple way and offers a secure, non-removable assembly, which transmits without difficulty the necessary rotation to the core of the projectile body . A sealing disc, independent of the propulsion cage, ensures reliable sealing, so that the powder gases, which are bothersome in particular when passing through the tube, no longer influence

negatively the supply hood.

  The embodiment according to the invention of the projectile tip made of glass fiber reinforced plastic allows on the one hand good stability and therefore high flight precision during flight and on the other hand during impact on a target multi-plate, for example in the case of missile launching, perfect penetration of the penetrator core through the target

  multiplate, by immediate decomposition of the point.

  The invention also allows perfect detection of the ammunition, by an arrangement on the periphery of a closed metal strip, in the case where the ammunition must be counted or removed from a tube.

  heated by the firing of a Gatling type weapon.

  The arrangement according to the invention of the throttle groove on the supply hood prevents the disadvantageous transmission, mentioned above, of the supply shock on the connection between the propulsion cage and the supply hood, the load advantageously being transmitted directly to the supply hood. Various other features and benefits

  of the invention appear from the detailed description

  following. Embodiments of the invention are shown by way of non-limiting examples on the

annexed drawings.

  FIG. 1 is a view in longitudinal section of a projectile with an under-calibrated propulsion cage, with a propellant charge socket connected, along a line designated by I-I in FIG. 2; Figure 2 is a cross-sectional view along line II-II of Figure i of the propulsion cage projectile and a supply hood; Figure 3 is a longitudinal half-section on the left side, on a larger scale, of the projectile with propulsion cage, with a view of the right side of the projectile shown in Figure 1 with projectile tip, propulsion cage, cover d 'inlet and sealing disc; Figure 4 is a longitudinal sectional view along the line I-I of Figure 2, of the supply hood; Figure 5 shows the propulsion cage half in a cross-sectional view lengthwise and half in a side view; FIG. 6 is a side view of the projectile core with a projectile point fitted into

the core.

  According to FIG. 1, a projectile 1 sub-

  calibrated, intended for stabilization in rotation, with a central longitudinal axis A, has a point 2 in the front zone. The projectile consists of a core i made of a material with a high density of approximately 18 to 19 g / cm3. The tip 2 of the projectile is conical on the outside and follows a frustoconical outer zone (23) before the core 1 of the projectile. The tip 2 is made of a glass fiber reinforced plastic material, preferably of glass fiber reinforced polyamide 6 or glass fiber reinforced polyamide 6.6, the proportion of glass fibers of the tip

  2 of the projectile being between 37% and 43%.

  A propulsion cage 5, supporting the rear support surface 24 of the core i of the projectile, made of a metal of reduced density and of great resistance, is preferably made of a very resistant aluminum alloy with resistance to minimum tension of 500 N / mm2. The propulsion cage 5 contains in its front lateral zone, peripheral grooves 9 (fig. 5), arranged in parallel on the periphery, which form a connection by concordance of shape with a supply hood 3, enveloping the core 1

and point 2 of the projectile.

  The feed hood 3 bears at the rear on a radial appendage 25 (FIG. 5) of the propulsion cage 5. On the feed hood 3 is made, at the rear, a throttling groove 8 , for fixing a propellant charge socket 15, known per se, which houses a propellant charge 29 inside and which is extended, in its rear zone, by a base G 26, which contains an extractor claw 27 and one

ignition chain 28.

  The supply cover 3 is closed in its front frontal zone 30 and is frustoconical in its front external zone b 31 and is extended, in the central zone 32, by a cylinder, which has a slightly larger diameter at the rear. This zone 33, of enlarged diameter, serves at the same time, during the passage through the weapon tube, of guide strip 4 and for the production of a rotation. In the central zone 32 of the supply hood 3, a metal strip 14 is placed on the outside side 13 for detecting projectiles. This metal strip can be applied in a simple manner by a known or projected screen printing method. For a perfect detection of the projectile, a metal strip 14 (fig. 3) which has given good results is a silver strip, the silver content of which is between 60% and 80%. The plastic feed cover 3 has internally four break points 7 (fig. 2), which are formed in the form of grooves, regularly spaced, in the interior surface of the feed cover 3, and which s' extend over its entire length, in particular also over the end of the cylindrical zone 33 and of the zone

  attachment 34 with the propulsion cage 5.

  Thanks to the presence of four break points 7 (FIG. 2), a homogeneous structure of the supply cover 3 is obtained during manufacture, which cannot be obtained for example, with a manufacture with three break points. Only the internal arrangement of the breaking points 7 also guarantees an external arrangement of the metal strip 14, because for perfect functioning of the metal strip 14,

  this must not be interrupted around the perimeter.

  The rear zone 34, shown in FIG. 4, of the bore 10 extending to the front zone 30 and adapted to the external contour of the core 1 and in part

7,2759,453

  of the point 2 of the projectile, is conical, before the

  connection with the propulsion cage 5.

  After introduction of the core 1 of the point 2 of the projectile into the supply hood, the connection with the propulsion cage is carried out in that the zone 34 is plastically deformed, under the effect of heat, and in this state, the propulsion cage 5, provided with parallel grooves 9, is guided in the bore 34, the supply hood 3 being able, in the heated state, to fill the free spaces of the grooves of the propulsion cage and to form an intimate and fixed connection with the propulsion cage 5, after cooling. The propulsion cage 5 is conical in the region of the grooves 9. To achieve greater safety in rotation relative to the supply hood 3, the propulsion cage 5 can be partially provided in the area

grooves, knurling 35.

  The rear front face 36 of the propulsion cage 5 forms a rectilinear application surface for an elastic seal 6, which is shaped as a disc 11 and which has a seal lip 12 directed towards the rear. This seal 6 can preferably be made of polycarbonate and ensures the seal, thanks to its elastic deformability, even in the case of extremely high pressures, relative to the tube (not shown) and also prevents penetration of the powder gases in the region of connection of the propulsion cage 6 with the supply hood 3. The sealing disc 11 can be assembled, in a simple manner, with the propulsion cage 5, by a snap-on assembly 16, this snap-on assembly being formed by an outer cone 17 of the propulsion cage 5 and a cone

  interior 18 adapted from the sealing disc 11.

  The point 2 of the projectile, shown in Figure 1, can be assembled in a different way

  with the core 1 of the projectile, according to Figures 3 and 6.

  FIG. 3 shows that the projectile core has a front appendage 21, intended to be pressed inside a rear hole 22 in the point 2 of the projectile, the point 2 bearing on the outside of this connection, with rear, on a conical surface 37

of the nucleus.

  FIG. 6 represents, on the other hand, a connection in which the point 2 of the projectile houses at the rear an appendage 19, which is pressed inside a bore 20 before the core of the projectile. In this embodiment, the tip 2 rests on a

  surface 38 rectilinear of the core 1 of the projectile.

  The previously described configurations of the sub-calibrated propulsion cage projectile according to the invention guarantee a reliable transmission of the rotation, from the supply hood 3, by the propulsion cage 5, to the core 1 of the projectile, the transmission of the cage propulsion to the nucleus using a

  shape matching not shown.

  Premature destruction of the supply hood, when passing through the tube, is prevented by the

  reliable sealing function of the sealing disc 11.

  Thanks to the advantageous properties, already mentioned, of the supply hood 3, the propulsion cage 5 and the point 2 of the projectile, it is possible to fight armored targets at least in places, rapid and maneuverable, for example helicopters combat and fast patrol boats as well as land vehicles. The use of a very resistant material for the projectile core, for example tungsten of high density and high coefficient of expansion, on the other hand makes it possible to effectively combat multi-layered targets, for example missiles.

Claims (13)

  1. - Projectile with propulsion cage under-   calibrated with a core (1) made of a material of high density with a point (2) as well as with a supply cover (3), having internal breaking points (7), which is connected by correspondence of form with a propulsion cage (5) made of light metal, the supply hood (3) being shaped at the rear as a guide strip (4), with a view to producing a rotation, and the whole of the propulsion cage projectile having a throttling groove (8) for assembly with a propellant charge socket (15), characterized by the following characteristics: a) the propulsion cage (5) contains, for the assembly of the supply hood (3), peripheral grooves (9) and the supply hood (3) contains a bore (10), which in this area is plastically deformed iO for the production of the assembly under the action of heat, and which, after cooling, fixedly surrounds the grooves (9), by concordance of shape; b) below the propulsion cage (5) is placed an elastic sealing disc (11) made of plastic material, which has a sealing lip (12) oriented towards the rear; c) the point (2) of the projectile is made of plastic reinforced with glass fibers; d) on the outer side (13) of the supply cover (3) is placed a metal strip (14), closed on the periphery, for detecting the projectile; e) the throttle groove (8) is located on the rear side of the supply hood (3), for fixing   of the propellant charge socket (15).   2. - Projectile propulsion cage according to claim 1, characterized in that the propulsion cage (5) and the perceag9e (10) of the supply hood   (3), is conical in the region of the groove (9).   3. - Propulsion cage projectile according to   either of claims 1 or 2, characterized   in that the propulsion cage (5) is made of a   very resistant aluminum alloy.   4. - Propulsion cage projectile according to claim 3, characterized in that the propulsion cage has a minimum resistance to O10 tension of 500 N / mm2.   5. - Propulsion cage projectile according to claim 1, characterized in that the sealing disc (11) is assembled to the propulsion cage   (5), by a snap-on assembly (16).   6. - Propulsion cage projectile according to claim 5, characterized in that the propulsion cage has, for the formation of the latching assembly (16), an outer cone (17) and the sealing disc (11), an inner cone (18).   7. - Propulsion cage projectile according to claim 1, characterized in that the point (2) of the projectile is made of polyamide 6 reinforced with fibers.   glass or polyamide 6.6 reinforced with glass fibers.   8. - Propulsion cage projectile according to   any one of claims 1 to 7, characterized   in that the proportion of glass fibers in the tip   (2) of the projectile is between 37% and 43%.   9. - Propulsion cage projectile according to   any one of claims 1 to 8, characterized   in that the point (2) of the projectile has at the rear an appendage (19), which is pressed inside a front bore of the core (1) of the projectile. 10. - Propulsion cage projectile according to   any one of claims 1 to 8, characterized   in that the projectile core (2) has a front appendage (21) intended to be pressed inside a rear hole in the point (2) of the projectile. 11. - Propulsion cage projectile according to claim 1, characterized in that the metal strip (14) is a silver strip, the content of which   in silver is between 60 and 80%.   12. - Propulsion cage projectile according to claim 11, characterized in that the silver strip (14) is applied by means of a method serigraphic or projected.   13. - Propulsion cage projectile according to claim 1, characterized in that the supply hood (3) has inside four break points arranged symmetrically and extending over all the length of the supply hood (3).