Projectile

Abstract

A projectile including a jacket, a core and a stabilizer part, the stabilizer part including a shaft and a fin part fastened to the shaft at the first end of the stabilizer part, whereby in the core of the projectile is a cylindrical cavity, which is closed at least partly with a shutoff part in which shutoff part is an aperture for the shaft of the stabilizer part, whereby a piston is fastened to the second end of the shaft of the stabilizer part, which piston is disposed in a cavity for forming a space at the front end of the piston and through the shaft of the stabilizer part a channel passes into the space and in the front part of the cavity is a solid fuel, which is made to ignite by means of the powder pressure produced in conjunction with firing of the projectile.

Claims

1. Projectile comprising a jacket, a core and a stabilizer part the stabilizer part comprising a shaft and a fin part fastened to the shaft at the first end of the stabilizer part whereby in the core of the projectile is a cylindrical cavity which is closed at least partly with a shutoff part, in which shutoff part is an aperture for the shaft of the stabilizer part, whereby a piston is fastened to the second end of the shaft of the stabilizer part, which piston is disposed in a cavity for forming a space at the front end of the piston and through the shaft of the stabilizer part a channel passes into the space in which case movement is brought about by powder pressure for pushing the stabilizer part out, wherein the front part of the cavity is solid fuel which when combusting maintains or accelerates the velocity of the projectile

2. Projectile according to claim 1, wherein the shaft of the stabilizer part widens as it approaches the piston and at the root of the piston is larger in diameter than the aperture of the shutoff part for fastening the stabilizer part with friction to the shutoff part.

3. Projectile according to claim 1, wherein the shaft of the stabilizer part comprises more than one part, which parts are telescopically openable and closable, and fasten to each other by means of friction in their open position.

4. Projectile according to claim 3, wherein the fin part is fastened to one of any of the parts of the telescopic shaft

5. Projectile according to claim 3, wherein the fin part comprises more than one part, which parts of the fin part are fastened to more than one part of the telescopic shaft.

6. Projectile according to claim 1, wherein the fin part of the stabilizer part is shaped to bring about rotational movement of the projectile around the axis of its own longitudinal axis.

7. Projectile according to claim 1, wherein the shutoff part is fastened to the inside surface of the cavity with threads

8. Projectile according to claim 1, wherein that on the jacket of the projectile is at least one sealing ring, which seals the projectile against the inside surface of the barrel.

9. Projectile according to claim 1, wherein the case is fastened to the shutoff part.

10. Projectile according to claim 1, wherein the case is fastened to the shutoff part and to the jacket of the projectile

11. Projectile according to claim 1, wherein the case is fastened to the jacket of the projectile

12. Projectile according to claim 1, wherein there is beveling in the channel at its space end.

13. Projectile according to claim 1, wherein the projectile further comprises a pressure detonator in the cavity for igniting the solid fuel

14. Projectile according to claim 1, wherein from the space of the cavity of the projectile are two or more channels in addition to the channel, from which channels the combustion gases of the solid fuel are able to exit from the space.

Description

[0013] In the following the invention will be described in more detail with the aid of some examples of its embodiment with reference to the attached simplified drawings, wherein

[0014] FIG. 1 presents a simplified schematic drawing of a preferred projectile according to the invention, before firing of the projectile, and

[0015] FIG. 2 presents a simplified schematic drawing of a preferred projectile according to the invention, after firing of the projectile.

[0016] The terms frontmost, front and the like hereinafter refer to the direction or surface corresponding to the direction of flight of the projectile and, correspondingly, the terms rearmost, rear and the like refer to the opposite direction or surface with respect to the direction of flight of the projectile. The longitudinal direction refers to the direction of the barrel of the weapon.

[0017] FIG. 1 presents a simplified schematic drawing of a preferred projectile 1 according to the invention, before firing of the projectile. The projectile comprises a jacket 2 and a core 3. The jacket 2 and the core 3 are typically the same material and the solution according to the invention is suited for use in all projectiles according to prior art. The projectile 1 is fastened to the case 4, whereby the case contains the detonator and powder (which are not presented in FIG. 1) needed for firing the projectile. When the weapon is fired, the detonator ignites the powder and the powder gas formed when the powder burns brings about movement of the projectile. The pressure of the powder gas forming in the case and later in the barrel makes the projectile move through the barrel providing the direction for the projectile.

[0018] In the core 3 of the projectile 1 is a cylindrical cavity 5, in which is disposed at least partly the stabilizer part 6, i.e. the tail fin, of the projectile. The cavity 5 is closed at least partly at its rear part with a shutoff part 25. The stabilizer part 6 comprises a fin part 7 and a shaft 8, to the first end 20 of which shaft the fin part is fastened, and also a piston 9 allowing movement and stopping of movement in the longitudinal direction of the stabilizer part, which piston is fastened to the second end 30 of the stabilizer part. The piston 9 of the stabilizer part 6 is disposed in the cavity 5 of the core 3 and is able to move in the longitudinal direction inside the cavity. In the shutoff part 25 of the cavity 5 is an aperture 26 for the shaft 8 of the stabilizer part 6. The shaft 8 of the stabilizer part 6 is able to move in the longitudinal direction inside the aperture 26 of the shutoff part 25. Before firing the projectile the stabilizer part 6 is positioned into its first extreme position according to FIG. 1, in which case the piston 9 at the second end of the stabilizer part is in its frontmost extreme position. The piston 9 of the stabilizer part 6, together with the cavity 5 formed in the core 3, forms a space 11 for the powder gases of the projectile 1 that are released in conjunction with firing the projectile. The powder gases pass into the space 11 along the channel 12 formed inside the shaft of the stabilizer part 6. The pressure of the powder gases makes the solid fuel 31 in the front part of the cavity 5 of the projectile 1 ignite. Alternatively, the solid fuel 31 can also be ignited with pressure detonators (not presented in the figures) that are activated by the powder pressure. The solid fuel 31 can be any solid fuel whatsoever known in the art that can be brought to ignite by means of the pressure of the powder gas or by means of a pressure detonator ignited by the pressure of the powder gas. Beveling 32 can be formed in the channel 12 at its space 11 end, in which case the mouth of the channel is shaped like a funnel. This shaping assists discharge of the combustion gases of the burning fuel from the chamber 5. The shaping is not mandatory, however, in which case the diameter of the channel 12 is constant for its full length.

[0019] The fin part 7 of the stabilizer part 6 is positioned against, or almost against, the rear part 13 of the projectile 1 before firing the projectile. The rear part 13 of the projectile 1 is formed at least partly by the shutoff part 25 enclosing the cavity 5 formed in the core 3 of the projectile. The shutoff part 25 is fastened to the projectile, to the inside surface of the rear part of the cavity 5, with threads 27. When it pushes out of the cavity 5 of the projectile 1 owing to the pressure brought about in the open space 11 by the powder gas, the fin part 7 of the stabilizer part 6 stabilizes the trajectory of the projectile 1 after the projectile exits the barrel of the weapon. The case 4 is in this embodiment fastened only to the shutoff part 25, but it is understandable that the case can extend also to the area of the jacket 2 of the projectile 1, whereby the case is fastened to both the jacket of the projectile and to the shutoff part. Likewise, the shutoff part 25 can be smaller in diameter than the diameter of the jacket 2 of the projectile 1 on the case 4 side, whereby the case is fastened exclusively to the jacket of the projectile.

[0020] On the outer surface of the jacket 3 of the projectile 1 are sealing rings 14, which seal the gap between the projectile and the barrel of the weapon. There can be one or more sealing rings 14 around the projectile. These sealing rings 14 prevent the powder gas from escaping to the front of the projectile 1 in the barrel of the weapon after firing of the projectile and enable the maximal acceleration and muzzle velocity for the projectile. The sealing rings are typically manufactured from copper, a copper-bronze alloy or a corresponding material suited to sealing.

[0021] FIG. 2 presents a simplified schematic drawing of a preferred projectile 1 according to the invention, after firing of the projectile. The powder gases released in conjunction with firing of the weapon are able to push into the space 11 formed inside the core 3 of the projectile 1 via the channel 12 passing through the shaft 8 of the stabilizer part 6 of the projectile. The pressure of the powder gas brings about expansion of the space 11, in which case the powder gases push the piston 9 at the end of the shaft 8 of the stabilizer part 6 from its first extreme position to its second extreme position and maximize the space 11 in the cavity 5 of the core 3 of the projectile 1. Simultaneously, the pressure of the powder gas makes the solid fuel 31 inside the projectile 1 ignite, and the solid fuel combusts in the cavity 5, in which case the expanded space 11 has now become a combustion chamber for the solid fuel. The combustion gases of the solid fuel 31 exit from the space 11 of the channel 12 and maintain the velocity of the projectile 1 or even accelerate it. The diameter of the channel 12 is dimensioned in such a way that the combustion gases of the solid fuel are able to be discharged from the space 11 at the desired velocity, and so that the pressure of the space 11 does not become too high. As a result of the solid fuel 31, the impact velocity of the projectile 1, i.e. its velocity at the moment of striking the target, is increased compared to a projectile without fuel.

[0022] In its second extreme position the rear surface 16 of the piston 9 is pressed against the shutoff part 25. The shaft 8 of the stabilizer part 6 and the aperture 26 of the shutoff part 25 are dimensioned in such a way that when the stabilizer part moves from its first extreme position to its second extreme position, the shaft of the stabilizer part is locked into its second extreme position by the effect of the pressure of the powder gases. The stabilizer part 6 staying in its second extreme position also helps the combustion gas pressure produced by combustion of the solid fuel 31. In a preferred embodiment two or more channels are fabricated through the piston 9 and the shut-off part 25 (not presented in the figures), through which the combustion gases produced when the solid fuel burns are brought to discharge from the space 11. The channels are disposed symmetrically around the center axis of the projectile. This allows the use of faster-combusting solid fuel 31 and an increase in the effect on the flight velocity of the projectile 1. The combined cross-sectional area of all the channels determines the selection of the burning rate of the solid fuel in use.

[0023] Locking of the stabilizer part 6 is brought about e.g. by making the shaft 8 of the stabilizer part 6, at least in the proximity of the piston 9, slightly thicker, in which case it is brought to jam in the aperture 26 of the shutoff part 25 when the stabilizer part moves into its second extreme position. As the shaft 8 of the stabilizer part 6 is firmly attached to the aperture 26 of the shutoff part 25, a pitch can be made in the fin 7 of the stabilizer part, the pitch enabling achievement of a rotational movement of the projectile 1 around its own longitudinal axis. The pitch of the fins 7 bring about the same effect on the projectile 1 as the rifling of the barrel of a weapon. In the solution according to the invention the barrel of the weapon is thus smooth-bore. The fins can also be shaped in some other manner in order to bring about rotational movement of the projectile around its longitudinal axis.

[0024] The solution according to the invention can, with regard to the stabilizer part 6, also comprise more than one shaft 8, in which case the parts of the shaft telescopically open and, due to friction, lock into their open extreme positions. Locking is brought about by making the sections of the shaft 8 very slightly conical, at least at the ends of the sections of the shaft, in such a way that in the open position of the shaft the external diameter of the end of an innermost section of the shaft is slightly larger than the internal diameter of an outer section of the shaft. In the closed position the parts of the shaft 8 are nested and they open only due to the pressure of the powder gases and wedge into the locked position. The fin part 7 can be fastened to any part of the shaft 8 whatsoever, in which case one or more parts of the shaft can further extend to behind the fin part. The fin part 7 can also be fastened to one or more parts of the shaft 8. Owing to the telescopic structure, the length of the projectile 1 can be increased and, if so desired, the fin part 7 can be disposed farther from the jacket 2 of the projectile. With this solution a more stable trajectory of the projectile 1 than before is obtained. Furthermore, the pressure in the space 11 brought about by the combustion gases produced during combustion of the solid fuel 31 helps to open, and to keep in the opened position, the parts of the shaft 8.

[0025] The charge of the projectile according to the invention is larger than that of a corresponding projectile according to prior art, in which case a higher muzzle velocity is obtained with the projectile and, as a result of the solid fuel, the velocity is maintained and even accelerated. A higher muzzle velocity and maintenance/acceleration of the velocity achieve a more stable trajectory and a higher impact velocity at the target. At the same time the targeting accuracy of the projectile improves compared to a conventional projectile. This is considerable, especially at long ranges of fire. At the same time the impacts caused by rifling on the trajectory and targeting accuracy of the projectile are eliminated. Rifling grooves affect the stability of a weapon and try to turn the barrel/tube of the weapon when the projectile is in the barrel/tube of the weapon. The effects of rifling on targeting accuracy are highlighted in particular when shooting rounds requiring accuracy at targets a long way away. Furthermore, some of the pressure of the powder gas is able to discharge via the rifling, in which case the type of smooth-bore solution of the invention utilizes the pressure generated more efficiently.

[0026] The projectile according to the invention also produces a double impact on striking the target, which is extremely effective in the case of armored targets. When the projectile hits its target, the first impact comes from the impact of the envelope and core. Simultaneously, the stabilizer part plus its piston and fins, starts moving forwards. As the stabilizer part hits the target slightly later than the jacket and core, the stabilizer part brings about a second impact on the target, which increases penetration effectiveness. In the case of an embodiment having a shaft 8 of telescopic structure, a number of impacts occur as the telescopic structure crumples after the hit.

[0027] It is obvious to the person skilled in the art that the invention is not limited solely to the examples described above, but that it may be varied within the scope of the claims presented below.