WO2000049362A1

WO2000049362A1 - A subcalibre ammunition

Info

Publication number: WO2000049362A1
Application number: PCT/CZ2000/000007
Authority: WO
Inventors: Ivo Exel; Zdeněk BUDIAČ; Alois KUŽELA; Jitka POLÁŠKOVÁ; Drahomíra VALENTOVÁ; Lubomír PRCHLÍK; Jan DROTÁR
Original assignee: Ivo Exel; Budiac Zdenek; Kuzela Alois; Polaskova Jitka; Valentova Drahomira; Prchlik Lubomir; Drotar Jan
Priority date: 1999-02-19
Filing date: 2000-02-16
Publication date: 2000-08-24
Also published as: AU2532400A

Abstract

For weapons of all calibres there is designed a subcalibre ammunition with a projectile (2) and a blow-off external jacket (1) provided with an internal jacket (3) furnished at the outer end with a central nozzle (7) housing an igniting explosive (13) and at the inner end accommodates a stabilising section of the projectile (2). The position of the projectile (2) in the external jacket (1) is defined by a front cap (12). The internal jacket (3) is equipped with an acceleration system.

Description

A SUBCALIBRE AMMUNITION

Technical Field

The invention relates to a subcalibre ammunition, provided with a projectile having a starter and a blow-off external jacket.

Background of the Invention

There is known a subcalibre ammunition comprising a cartridge with a power charge and a shell with a subcalibre projectile and releasing segments. After leaving the gun barrel the segments automatically separate from the projectile. Known shells are based on a single stage principle, without any additional acceleration. Therefore the projectile initial, muzzle velocity is given only by kinematic energy, provided by firing of the charge and by the shell system mass. Subcalibre ammunition operates as follows. It is loaded into a firing chamber and fired. When leaving the barrel muzzle, due to the combined action of gas and aerodynamic forces the segments separate from the projectile which travels toward a target along an extremely flat trajectory. The projectile pierces the target object with an kinetic energy produced by a body of a given mass and velocity. Known subcalibre shells manifest undesired frequency instability during flight due to a deceleration after leaving a barrel muzzle. The resulting, relatively low velocity is thus provided for only by the cartridge powder load. Subcalibre projectiles show low strain work during impact upon a target.

As far as the projectile is concerned, known constructions of various calibres, irrespective of the weapon, have a body which at its end other than the point, completed by a section, having substantially a shape of a truncated cone, tapering toward the projectile end. The projectile bottom is mostly a flat surface. There are also used solid wings, but they prevent rotation of the projectile. Known designs result in a high turbulent flow in the projectile end region, negatively influencing the projectile flight stability and strike accuracy. For starting of sprinter-explosive and sprinter-incendiary projectiles there are used head starters, i.e. starters located in a projectile points. Such a starter comprises striking and self-destruction mechanisms, safety and a booster. The striking mechanism includes an impacting component lock, a releaseable sleeve, safety spiral and an impacting component with a needle. The self-destruction mechanism includes a housing with a delay explosive and a striking element to start the delay explosive. The self- destruction mechanism is followed by a safety, a primer and a booster to start the projectile blasting agent. When hitting a target the striking mechanism starts the primer which starts the booster and subsequently the blasting agent is discharged. In a case the projectile misses the target it is destroyed by the self-destruction mechanism. The starter of the said type is not applicable by piercing and subcalibre ammunition furnished with a blasting agent. It is an object of the invention to remove drawbacks of the present subcalibre ammunition and to increase piercing power of a projectile of a particular barrel calibre

It is a further object of the invention to improve a stability of known projectiles and to increase effects of a hit. It is still a further object of the invention to improve a projectile starter to enable applications in a projectile rear part.

Disclosure and Object of the Invention

The object is achieved and the problems are solved by a subcalibre ammunition, provided with a projectile having a starter and a blow-off external jacket in an embodiment according the present invention where the external jacket accommodates an inner jacket provided with an acceleration system. The acceleration system preferably comprise an explosive mixture and/or a gas developing combustible. As another feature of the invention the inner jacket is at one its end equipped with a central nozzle housing a igniting explosive and on the its other end allows for a seat of a lower part of the projectile. A position of the projectile in the external jacket is defined by the projectile front cap. In a preferred embodiment the internal jacket inside space is at the end adjacent to the central nozzle closed by a baffle plate equipped with multiple openings the centres of which are located on at least one pitch circle, which is co-axial with the ammunition longitudinal axis, provided that an axis of at least one of the openings is inclined with respect to the said longitudinal axis.

Further in accordance with the present invention the projectile stabilising section is provided with an underpressure jet system. In another preferred embodiment the projectile body comprise a tapered entering part which through a convex intermediate part and a following converging part merges into the spherical end part. The end part together with the transient portion of the converging part provides for the stabilising section of the projectile. The underpressure jet system preferably comprise at least three side channels inclined with respect to the projectile longitudinal axis and towards the projectile point. The channels open into a central channel, running coaxially with the projectile longitudinal axis and opening on a surface of the spherical end part of the projectile.

According to another preferred feature of the invention the entering part is provided with an electrically conducting surface, the intermediate part with an electromagnetic circuit, isolated from the intermediate part surface and the stabilising section is of an electrically conducting material coated by an electrically non-conducting material, provided the electromagnetic circuit is conductively connected with surfaces of the entering and the stabilising parts. In a particular preferred embodiment the entering part is of a heavy metal, preferably of a wolfram, the heavy metal layer being coated with an electrical conductive layer, preferably of silver and/or copper and/or their alloys. The entering part is preferably provided with a coating of titanium nitrate. In a further preferred embodiment the electromagnetic circuit comprise a system of stripes of an electrically conductive material the stripes being advantageously arranged in at least one helix.

Still further in accordance with the invention the projectile is provided with a bottom starter, which is preferably located in the projectile stabilising section. The starter chamber is by means of a connection channel connected with the central channel at its end meeting with the side channels. According to another particular preferred feature of the invention the starter is provided with a first cylindrical cavity accommodating a slideably seated impacting component with a needle. The needle protrudes into a second cylindrical cavity and is surrounded by a safety spiral defining a space between the needle and the primer, which is located in a package comprising also at least one delay explosive positioned behind the primer. The delay explosive is followed by a booster, which protrudes from the starter body. A space between the impacting component needle and the primer is preferably divided by a partition wall. Preferably a separation plate is located between the delay explosives and the booster.

According to the first aspect of the invention there is provided a subcaliber ammunition with a significantly increased strain work during impact upon a target with a minimised possibility of a rebound.

According to another aspect of the invention there is provided a projectile with improved flight stability showing very little possibility of a deflection when hitting an inclined obstacle. The fact that a turbulent streamline flow in the projectile rear region is reduced to a very low level results also in an increased piercing power. This power is further increased by effects of the projectile own electromagnetic field, which before the very impact of the projectile upon the target hampers particle stability of the material in the hit region. The projectile of the design hereby discussed may be applied also for a standard ammunition and even fired form other pressure and power facilities.

According to still another aspect of the invention there is provided a starter of a very simple construction and thus of very low production costs. The delay explosives allow for blasting a projectile after it penetrates into a target obstacle. Advantageously the fuse can be located in a projectile rear part Brief Description of the Drawings

By way of examples the invention will be now described with reference to the accompanying drawing. Fig. 1 shows a subcalibre ammunition in a Brief Description of the Drawings

By way of examples the invention will be now described with reference to the accompanying drawing. Fig. 1 shows a subcalibre ammunition in a side sectional view, Fig. 2 presents a projectile in a side sectional view and Fig. 3 schematically illustrates distribution of an electromagnetic circuit on a projectile surface. On Fig. 4 there is shown a starter in a side sectional view.

Description of Preferred Embodiments

Referring to Fig. 1 , there is shown a subcalibre ammunition comprising external jacket carrying co-axially and in succession arranged a projectile 2 with a blasting agent 40 and an internal jacket 3, which accommodates an acceleration system 14.

The internal jacket 3 is at the side opposite the projectile 2 position closed by a baffle plate 5 with multiple openings 6, the centres of which are distributed along at least one pitch circle being coaxial with a longitudinal axis 15 of the ammunition. It applies that an axis of at least one of the openings 6 is inclined with respect to the longitudinal axis 15. At the very same end the internal jacket 3 is completed with a central nozzle 7, housing an igniting explosive 13. At its other end the internal jacket 3 is closed by a porous insert 8 and at the outer surface it is equipped with a step, on which there is seated a sleeve 4. The sleeve 4 supports the projectile 2, particularly its lower part and more particularly its stabilising section, which is in details discussed further on. With respect to the external jacket 1 the projectile 2 position is defined by means of the external jacket 1 front cap 12, through which the projectile 2 protrudes. The ring-shaped front cap 12 has a substantially cone-like inside surface, corresponding to the shape of the adjacent projectile 2 body, and a concave face surface, i.e. the surface facing a direction of a gunfire. In the sleeve 4 the projectile 2 is secured by at least three sealing means 11., preferably evenly distributed along the sleeve 4 periphery and matching with corresponding concave holes 20 appropriately located at the projectile 2 surface. The concave holes 20_ improve contact between the projectile 2 body and the sealing means H, but they are not indispensable. Inside the sleeve 4 there is a free space 16 of a substantially ring shape, surrounding the projectile 2 rear part. The external jacket 1 is equipped with at least one guiding ring 9 and at the bottom, i.e. at the end opposite the projectile 2 position, with a rear cap 10. The guiding ring 9 allows also for sealing purposes. The rear cap 10, which is of a ring shape, supports the igniting explosive 13 inside the central nozzle 7 and simultaneously the bottom end of the external jacket 1.

As the acceleration system 14 there can be used any explosive mixture or any combustible with enormous development of gases.

The projectile 2 rear part may be supported directly by the inner jacket 3, without the sleeve 4. Such a construction would simplify the design but would deteriorate the further discussed effects.

The subcalibre ammunition as described above operates as follows. When fired there is discharged the igniting explosive 13 and after leaving the barrel the external jacket 1 is separated, the action being facilitated by the face shape of the front cap 12 Due to a discharge of the igniting explosive 3 the acceleration system 14 inside the inner jacket 3 starts to fire. Produced gasses escape through baffle plate 5 openings 6 and the central nozzle 7, thus accelerating the projectile. Due of overpressure in the internal jacket 3, certain amount of gasses penetrates through the insert 8 into the free space 6 between the sleeve 4 and the projectile 2 rear part, where the pressure increases and helps the projectile 2 to release from the internal jacket 3. The accelerated projectile 2 continues its flight as a single, separate body. When hitting the target there is activated its bottom starter 30, starting the projectile blasting agent 40.

As presented on Fig. 2, the projectile 2 body according the invention comprise a tapered entering part 21, a convex intermediate part 22 and a converging part 23 merging into a spherical end part 24. The converging part 23 together with the transient portion to the end part 24 provides for the projectile 2 stabilising section. Inside the end part 24 there is located an underpressure jet system, which comprise multiple channels 26, at least three of them, the axis of which being tilted with respect to the longitudinal axis 15 of the projectile 2 and terminating in a central channel 27 which is coaxial with the longitudinal axis 15 and at its first end opens on the end part 24 surface. On its other end the central channel 27 is by means of a connection channel 28 connected with a chamber of the bottom starter 30 for starting the blasting agent 40 located in the projectile 2 body.

The shape of the stabilising section allows for a smooth flow of streamlines along the lower part of the projectile 2 body without separation towards the end thus facilitating the projectile 2 flight stability.

The projectile 2 need not necessarily to be furnished with the blasting agent 40 and the starter 30.

The projectile 2 according the said preferred embodiment apart from application in the above presented subcalibre ammunition may be utilised separately for ammunition without the blow-off jacket and the acceleration system 14.

The projectile 2 body may be provided with a surface coating for a protection of the barrel bore. Such a coating is not shown on the drawings. In another preferred embodiment presented in Fig. 3, the entering part 2 _. is made of a heavy metal, preferably of a wolfram, and is provided with an electrically conductive layer of a metal like copper, silver or their compositions, the layer allowing for the first electrode. The conductive layer is preferably coated by a reinforcing layer of a titanium nitrate. The intermediate part 22 surface is provided with an electromagnetic circuit, comprising stripes 29 of an electrically conductive material like copper, silver or their alloys or mixture of the metal and its alloy. The stripes 29, isolated from the intermediate part 22 surface, are preferably arranged into a helix running around the projectile 2 body. The helix is either right-hand or left- hand oriented, the orientation corresponding to the orientation of the bore of the respective gun barrel. The converging and rear parts 23,24 are of an electrically conductive material, allowing for the second electrode. The entering part 21 as well as the converging and rear parts 23,24 are electrically connected with stripes 29 of the electromagnetic circuit. The stabilising section is coated by en electrically non-conductive layer, like aluminium oxide and/or elox layer, providing for a mechanical protection. For the purpose also a dielectric layer may be used.

The hereby revealed projectile 2 operates followingly. During flight there is induced an electromagnetic charge on the projectile 2 surface, the entering part 21 receiving a charge of an opposite polarity than the rear part 24, and simultaneously, because of the environmental magnetic field, there is induced an electric current in the electromagnetic circuit, the current creating an electromagnetic field of the projectile 2. Creation of the current supports rotation of the projectile 2 around its longitudinal axis 15. The preferred embodiment of the starter 30, as presented on Fig. 4, comprise the body 3_H, a first cylindrical cavity, in which there is displaceably seated an impacting component 301 with a needle. Around the needle, in a second cylindrical cavity having a diameter larger than the diameter of the first cavity, there is arranged a spiral fuse 302, defining a space between the needle and a primer 303, which is fitted in a package 310 also screwed in the body 3_H. In the package 310, behind the primer 303, there are located two one delay explosive 304. In general at least one delay explosive 304 is necessary. Behind the delay explosives 304, seating in a plug screw 306, there is placed a booster 307, protruding from the body 311. The space above the impacting component 301 needle is separated from the primer 303 by a safety partition wall 309. Between the delay explosives 304 and the booster there is a separation plate 305. Assembly holes 308 facilitate completion of the starter 30 and its accommodation into the projectile 2. All the elements may be inserted into the body 31 1 also from the other starter 30 end, starting with the booster 307 and ending with the impacting component 301 with a needle. In such a case the impacting component 30_1 with a needle is seated in a second package, which is also screwed in the body 311.

The starter 30 operates as follows. During the projectile 2 rotation while in the air, the spiral fuse 302 gets loose and unblocks the impacting component 301 with the needle. When hitting the target the impacting component 301 needle starts the primer 303 which starts the delay explosive 304 which fires the booster 307. The booster 307 subsequently activates the blasting agent 40..

Industrial applications

The present invention is designed for a sub-calibre ammunition on any calibre as well as for bombs, mines, grenades and rockets.

Claims

C L A I M S

1. A subcalibre ammunition, provided with a projectile having a starter and a blow-off external jacket, characterised in, that the external jacket (1) accommodates an inner jacket (3) provided with an acceleration system (14), the inner jacket (3) being at one its end equipped with a central nozzle (7) housing a igniting explosive (13) and on the its other end allowing for a seat of a lower part of the projectile (2), the position of which in the external jacket (1) is defined by the projectile (2) front cap (12).

2. A subcalibre ammunition according to claim 1 , characterised in, that the projectile (2) is attached in the internal jacket (3) by means of a sleeve (4) located at the internal jacket (3) front part, the projectile (2) body being fixed in the sleeve (4) by at least three sealing elements (11), provided that the internal jacket (3) end, adjacent to the projectile (2) is closed by a porous insert (8) and between the sleeve (4) and the projectile (2) stabilising section there is a free space (16).

3. A subcalibre ammunition according to claim 1 or 2, characterised in, that at the end adjacent to the central nozzle (7) the internal jacket (3) inside space is closed by a baffle plate (5) equipped with multiple openings (6) the centres of which are located on at least one pitch circle, co-axial with the ammunition longitudinal axis (15), provided that an axis of at least one of the openings is inclined with respect to the said longitudinal axis (15). -

4. A subcalibre ammunition according to claim 1 , 2 or 3, characterised in, that the projectile (2) stabilising section comprise an underpressure jet system.

5. A subcalibre ammunition according to any of the preceding claims, characterised in, that the projectile (2) is provided with a bottom starter (30)

6. A subcalibre ammunition according to any of the preceding claims, characterised in, that the acceleration system (14) is provided with an explosive mixture and/or a gas developing combustible.

7. A subcalibre ammunition according to any of the preceding claims, characterised in, that the projectile (2) body comprise a tapered entering part (21) which through a convex intermediate part (22) and a following converging part (23) merges into a spherical end part (24), the converging part (23) together with the transient portion to the end part (24) providing for the projectile (2) stabilising section.

8. A subcalibre ammunition according to claim 4 or 7, characterised in, that the underpressure jet system comprise at least three side channels (26) inclined with respect to the projectile (2) longitudinal axis (25) and towards the projectile (2) point, the channels (26) opening into a central channel (27), running coaxially with the projectile (2) longitudinal axis (25) and opening on a surface of the spherical end part (24) of the projectile (2).

9. A subcalibre ammunition according to claims 5 and 8, characterised in, that the bottom starter (30) is located in the projectile (2) stabilising section, its chamber being by means of a connection channel (28) connected with the central channel (27) at its end meeting with the side channels (26).

10. A subcalibre ammunition according to any claim from 7 to 9, characterised in, that the entering part (21) is provided with an electrically conducting surface, the intermediate part (22) with an electromagnetic circuit, isolated from the intermediate part (22) surface and the stabilising section is of an electrically conducting material coated by an electrically non-conducting material, provided the electromagnetic circuit is conductively connected with surfaces of the entering and the stabilising parts

11. A subcalibre ammunition according to any claim from 7 to 10, characterised in, that the entering part (21) is of a heavy metal, preferably of a wolfram, the heavy metal layer being coated with an electrical conductive layer, preferably of silver and/or copper and/or their alloys.

12. A subcalibre ammunition according to any claim from 7 to 11 , characterised in, that the entering part (21) is provided with a coating of titanium nitrate.

13. A subcalibre ammunition according to claim 10, characterised in, that the electromageticl circuit comprise a system of stripes (29) of an electrically conductive material.

14. A subcalibre ammunition according to claim 10, characterised in, that for the an electrically conductive layer of the stabilising section there is applied aluminium and/or its alloy.

15. A subcalibre ammunition according to claim 10, characterised in, that for the an electrically non-conductive layer of the stabilising section there is applied aluminium oxide and/or elox and/or dielectric material.

16. A subcalibre ammunition according to claim 10, characterised in, that the stripes are arranged in at least one helix.

17. A subcalibre ammunition according to claim 5 or 8, characterised in, that the starter (30) is provided with a first cylindrical cavity accommodating a slideably seated impacting component (301) with a needle, the needle protruding into a second cylindrical cavity and being surrounded by a safety spiral (302) defining a space between the needle and the primer (303), which is located in a package (310) comprising also at least one delay explosive positioned behind the primer, the delay explosive (304) being followed by a booster (307) protruding from the starter body (311).

18. A subcalibre ammunition according to claim 17, characterised in, that a space between the impacting component (301) needle and the primer (303) is divided by a partition wall (309).

19. A subcalibre ammunition according to claim 17 or 18, characterised in, that between the delay explosives (304) and the booster (307) there is located a separation plate (305).