DE9116281U1 - Device for limiting the range of vane-stabilized sub-caliber arrow projectiles - Google Patents

Description

Device for limiting the range of wing-stabilized, cable-guided arrow projectiles

As a result of the improvement in the performance of modern high-performance bullets, sub-caliber arrow bullets with sabots were developed.

Due to the low cross-sectional load (ratio of the bullet mass to the bullet cross-section) when fired, such a bullet has a very high initial speed when passing through the barrel. After leaving the barrel and after the sabot has detached, the cross-sectional load is significantly increased, which means that the arrow body, which is then exposed, only experiences a slight drop in speed due to its now relatively high weight and low air resistance.

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Since such projectiles are usually fired from smoothbore guns, conventional spin stabilization is not possible. Stabilization is achieved here by a tail unit attached to the rear of the arrow projectile, which consists of evenly distributed

tail fins.

Projectiles of the type described have the great disadvantage that, due to their great range and penetrating power, they can only be used for training and testing purposes on short shooting ranges with great safety measures.

For example, significant structural measures must be taken in order to catch and render harmless the projectile after it has penetrated a window.

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A significant improvement is the development of sub-caliber arrow projectiles with a reduced range. For this purpose, an aerodynamically unfavourable design of the tail unit causes an increase in air resistance, which leads to a rapid

|U. 35 leads to a reduction in the speed of the projectile and thus significantly reduces its range.

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Such measures are described, for example, in the DE - OS 27 47 313, where a sub-caliber arrow projectile with a Hole cone tail unit is described.

Furthermore, DE - OS 31 22 356 also shows a sub-caliber projectile with a reduced range, which consists of longitudinal tubes evenly spaced around the circumference of the arrow projectile. Due to the internal shape of the tubes, an aerodynamic drag occurs during the flight phase, which in certain speed ranges causes a drastic increase in the c value and thus a significant decrease in speed.

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The disadvantage here is that combat ammunition cannot be used for training purposes, but a special type of ammunition must be created specifically for this purpose. This results in high development and procurement costs as well as extensive logistics. Furthermore, existing combat ammunition that has become useless after a specified storage period must be decommissioned, which also causes considerable costs.
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The invention is therefore based on the object of creating a device which is suitable for modifying a combat cartridge so that it can also be used as a training cartridge with a reduced range.

The problem is solved on the basis of the features of the generic term of claim 1 by the features of its characterising part.

Attaching the sleeve according to the invention to the fleet tail unit of a sub-caliber arrow projectile has the great advantage that combat projectiles can be converted into training projectiles at any time with little effort. All that is required is

the separation and reassembly of the projectile and the combustible casing containing the propellant charge. For this purpose, the casing can be designed in two parts, with detachable connecting elements, such as a screw connection, plug connection or bayonet lock, arranged at the separation point. In principle, the separation can also take place directly at the casing-sabot connection point. A two-part casing design can be omitted in this case.

The air passage according to the invention makes it possible to also provide the practice projectile with a tracer set. This passage allows a small amount of air to flow parallel to the projectile's longitudinal axis to the rear of the projectile. The geometry of the air passage is so small that the air flow is just large enough to compensate for the suction of the projectile into the ground, which in itself inhibits the development of a tracer or prevents it from developing at all.

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The invention will be explained in more detail using an embodiment.

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The drawing shows Figure 1 The cuff according to the invention in section

the figure 2

The cuff according to the invention in front view.

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Figure 1 describes a wing tail assembly 8, which consists of tail fins 3 evenly arranged around the circumference of a dart projectile body 5, also known as a penetrator, with each fin being provided with a bevel 3' pointing towards the tip of the projectile. A tracer with a cup 4 is installed at the tail of the projectile at the end of the dart projectile body. The wing tail assembly 8

is surrounded by a truncated cone-shaped sleeve 2, which lies flush on the bevel 3' of any tail fin 3. The sleeve 2 can be designed to be circular all the way round or polygonal all the way round, with the latter case the sleeve surface representing the shortest path from one bevel 3' to the adjacent one.

The sleeve 2 is further equipped with an air passage 9, through which air can flow to the rear of the projectile and thus compensates for the suction from the ground so that a tracer can develop.

The air passage 9 can be designed as shown in Figure 1. In the case described here, the sleeve 2 does not quite reach the arrow projectile body 5. The air passage 9 thus has the shape of a circumferential annular gap. It is also possible, however, for the sleeve 2 to lie flush against the arrow projectile body and for an air passage to be arranged in the sleeve 2 itself, which consists of relatively small openings evenly spaced around the circumference of the sleeve 2 near the arrow projectile body. The openings themselves can be round, oval or even square. The sleeve 2 is, as Figure 1 clearly shows, towards the rear of the arrow projectile ₍ continuously over the actual contour of the fin tail unit).

A. It therefore not only closes the gaps between the tail fins 3, which in itself brings with it a drastic increase in c-value, but also increases the

including the total area over the actual fin unit 8

', which results in a further increase in air resistance.

^· The cuff 2 is mounted on the tail fins 3 in the manner described

jV: supported in this area by a circumferential abutment disc 1.

Figure 2 shows the arrow projectile 5 with the sleeve 2 according to the invention from the front. The fin tail 3, 3', as well as the sleeve 2 extending beyond it and the air passage 9 designed as an annular gap can be clearly seen.

Furthermore, Figure 2 shows two separating joints 10, which are used for the assembly

the cuff 2 is important.

The sleeve 2 is manufactured in such a way that it receives its final shape, but a segment is cut out in the outer surface and is inserted and secured on the tail unit 8 after assembly. The size of the segment is selected so that the sleeve can be pushed onto the arrow projectile body 5 in a radial direction and pushed or lowered onto the fin tail unit 8. After this process, the segment (not described in more detail) is reinserted and firmly connected to the remaining sleeve body at the joints 10. The connection can be designed as a weld or a positive connection.

Claims (3)

FEDERAL REPUBLIC OF GERMANY represented by the FEDERAL MINISTER OF DEFENCE represented by the PRESIDENT OF THE FEDERAL OFFICE FOR DEFENSE TECHNOLOGY AND PROCUREMENT DE Protection claims 1) Device for limiting the range of a wing-stabilized sub-caliber arrow projectile, which is equipped at the rear with a conical fin unit consisting of individual fins evenly arranged around the circumference characterized, that the fin unit (8) is surrounded by a truncated cone-shaped sleeve (2) which has an air passage (9) in the immediate vicinity of the arrow projectile body (5). 2) Device according to claim 1 , characterized in that that the air passage (9) consists of openings evenly arranged around the circumference of the cuff (2). 3) Device according to claim 1 , characterized in that that the air passage (9) consists of a circumferential annular gap.