Projectiles

Abstract

An assembly (2) for attachment to a projectile comprises a first part (4) and a second part (6) mounted for rotation relative to the first part (4) about an axis (A). There is an axial gap (G) between the first and second parts (4, 6). At least one plastically deformable element (34) is arranged within the gap (G) between the first and second parts (4, 6), the plastically deformable element (34) being such as to deform due to the closing of the axial gap (G) between the first and second parts (4, 6) during launch of the projectile.

Claims

1. A projectile comprising: a first part (4); a second part (6) mounted for rotation relative to the first part (4) about an axis (A); an axial gap (G) between the first and second parts (4, 6); and a plurality of permanently deformable element (34) arranged within the gap (G) between the first and second parts (4, 6), the permanently deformable element (34) being such as to deform permanently due to the closing of the axial gap (G) between the first and second parts (4, 6) during projectile launch; wherein the plurality of permanently deformable elements are circumferentially spaced around an axis (A).

2. The projectile as claimed in claim 1, wherein the deformable element (34) is arranged between opposing faces (30, 32) of the first and second parts (4, 6).

3. The projectile as claimed in claim 1, wherein the deformable element (34) is mounted to first part (4) or the second part (6) and retained thereby.

4. The projectile as claimed in claim 1, wherein the deformable element (34) is a plastically deformable element.

5. The projectile as claimed in claim 4, wherein the plastically deformable element is a metallic element.

6. The projectile as claimed in claim 1, wherein the deformable element (34) is constructed as a body of permanently deformable material.

7. The projectile as claimed in claim 1, wherein the deformable element (34) is cylindrical.

8. The projectile as claimed in claim 1, wherein the deformable element (34) is strip-like.

9. The projectile as claimed in claim 8, wherein the deformable element (34) is arcuate and extends either completely or incompletely circumferentially around an axis (A).

10. The projectile as claimed in claim 1, further comprising axial biasing means (24) arranged between the first and second parts (4, 6) for biasing the first and second parts (4, 6) apart.

11. The projectile as claimed in claim 1, further comprising a bearing (16) provided between the first and second parts (4, 6) for facilitating the rotation of the second part (6) relative to the first part (4).

12. An assembly (2) for attachment to a projectile, the assembly (2) comprising: a first part (4); a second part (6) mounted for rotation relative to the first part (6) about an axis (A); an axial gap (G) between the first and second parts (4, 6); and a plurality of deformable element (34) arranged within the gap (G) between the first and second parts (4, 6), the deformable element (34) being such as to deform permanently due to the closing of the axial gap (G) between the first and second parts (4, 6) during projectile launch; wherein the plurality of permanently deformable elements are circumferentially spaced around an axis (A).

13. The assembly as claimed in claim 12, wherein the deformable element (34) is arranged between opposing faces (30, 32) of the first and second parts (4, 6).

14. The assembly as claimed in claim 12, wherein the deformable element (34) is mounted to first part (4) or the second part (6) and retained thereby.

15. The assembly as claimed in claim 12, wherein the deformable element (34) is a plastically deformable element.

16. The assembly as claimed in claim 15, wherein the plastically deformable element is a metallic element.

17. The assembly as claimed in claim 12, wherein the deformable element (34) is constructed as a body of permanently deformable material.

18. The assembly as claimed in claim 12, wherein the second part (6) is a tip part and the first part (4) is a base part comprising means (18) for mounting the assembly (2) to the projectile.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) An embodiment of the disclosure will now be described, by way of example only, with reference to the following drawings in which:

(2) FIG. 1 shows a side perspective view of an assembly in accordance with this disclosure for attachment to a projectile;

(3) FIG. 2 shows a sectional view along the line II-II of FIG. 1; and

(4) FIG. 3 shows a view along line III-III of FIG. 2 of a base part of the assembly.

DETAILED DESCRIPTION

(5) With reference to the Figures, an assembly 2 for attachment to the head of a projectile, such as a shell, is shown.

(6) The assembly 2 comprises a first, base part 4 and a second, tip part 6 which is rotatable relative to the first, base part 4 about the longitudinal axis A of the assembly 2. The first, base part 4 is made from a metallic material and has a threaded region 8 for threadingly engaging a thread provided on the body of the projectile to secure the assembly thereto.

(7) The second, tip part 6 houses components 10, for example electronic components and has a plastics cap 12 at one end. It also has a depending spigot portion 14 which extends into the first, base part 4. A bearing 16 is provided between a bore 18 formed in the first, base part 4 and a locating element 20 mounted on the outer surface 22 of the spigot portion 14. A retaining element 24 is mounted to the locating element 20 so as to retain the second, tip part 6 on the base part 4. However, the connection between the locating element 20 and the tip part 6 allows the tip part 6 to move axially relative to the locating element 20 and therefore relative to the base part 4 as will be described further below.

(8) The tip part 6 is biased away from the base part 4 by means of biasing means 24, for example a Belleville washer 24, which is located between the bearing 16 (which is fixedly attached to the base part 4) and a depending lip 26 of the tip part 6. The effect of this bias is to create a gap G between a lower annular surface 30 of the tip part 6 and an upper, opposing, annular surface 32 of the base part 4. The purpose of this gap G is to facilitate the rotation of the tip part 6 about the axis A of the projectile relative to the base part 4. In some embodiments, the gap may be of the order of 0.5 mm, but this may vary depending on the particular application.

(9) As can best be seen from FIG. 3, a plurality of plastically deformable elements 34 are mounted on the upper annular surface 32 of the base part 4. In this embodiment, the deformable elements 34 are formed as solid cylinders of a deformable material, for example a deformable metal such as Aluminium. The elements 34 may be forged, cast, moulded, sintered etc. The deformable elements 34 are arranged in a circumferential array around the axis A.

(10) The deformable elements 34 are sized such that they substantially extend across the gap G at rest. Thus the deformable elements 34 abut or are very closely adjacent the lower annular surface 30 of the tip part 6.

(11) In use, the assembly 2 will be mounted on the tip of a projectile and launched. This will create very large accelerations and high forces. Should the tip part 6 impact the base part 4, then the impact force may set up damaging vibrations in the tip part 6 which could potentially damage at least the plastics cap 12. However, the deformable elements 34 mitigate this problem.

(12) When the projectile is launched at high acceleration, the tip part 6 will move downwardly relative to the base part 4, which will act to close the gap G between the two parts. However, due to the presence of the plastically deformable elements 34, rather than the tip part 6 impact upon the base part 4, the forces generated by the movement will be absorbed in plastically deforming the deformable elements 34 which will reduce in height, allowing the gap G to close somewhat. This prevents, or minimises, any impact forces between the base part 4 and the tip part 6 thereby avoiding or reducing any potentially damaging forces or vibrations in the tip part 6 which might otherwise damage the cap 12 for example.

(13) After launch and deformation of the deformable elements 34, the spring 24 will bias the tip part 6 away from the base part 4 to re-establish the gap G, thereby allowing the tip part 6 to rotate relative to the base part 4, as required.

(14) It will be appreciated that the above description is that of just one non-limiting embodiment of the disclosure and that various modifications may be made thereto without departing from the scope of the disclosure.

(15) For example, the material, construction, number, shape and arrangement of the deformable elements may be varied, as discussed in the introduction. Also, the particular arrangement of the two parts may vary and they need not necessarily form a tip portion of the projectile.

(16) Also, the deformable elements 34 may be mounted to the tip part 6 rather than the base part 4 or even mounted to an intermediate member.

(17) The deformable elements 34 may take a different form from those disclosed. Rather than being a plastically deformable body as disclosed, they could be of any permanently deformable construction, for example a collapsible structure. What is important is that the elements 34 permanently deform such that they do not act to close the gap G after launch.

(18) Also, it will be appreciated that the assembly may be fitted to new equipment or retrofitted to existing equipment by appropriate means. Thus means other than the screw thread 18 may be provided if appropriate.