GB2052694A

GB2052694A - A Projectile Housing

Info

Publication number: GB2052694A
Application number: GB8019142A
Authority: GB
Original assignee: Rheinmetall GmbH
Current assignee: Rheinmetall Industrie AG
Priority date: 1979-06-13
Filing date: 1980-06-11
Publication date: 1981-01-28
Also published as: FR2458789A1; GB2052694B; DE2923901C2; DE2923901A1; FR2458789B3

Abstract

A hollow, elongated projectile housing comprises a base (11) and a nose (12) joined by a tubular wall (10) made up of adjacent, coaxial rings (18) adhesively secured together. The invention provides the improvement that the rings (18) have interfitting, axially extending formations (19) and (20) to prevent radial dislodgement of the rings (18) so that the tubular wall can consist solely of the rings (18) without the need for an internal or external casing. In modifications of the invention the interfitting formations may be either annular or radial of the rings, and two adjacent rings with annular recesses may be joined by a separate annulus received in both. The inner peripheries of the rings may be formed to give the interior of the wall a bowed configuration and are preferably axially grooved to facilitate fragmentation. <IMAGE>

Description

SPECIFICATION A Projectile Housing This invention relates to an improved housing for an explosive projectile, such as a shell or othe missile.

A projectile is known from French Patent Specification No. 1,257,604 which has an elongated, hollow housing for the explosive comprising a nose portion and a base portion joined by a tubular wall which comprises a tubular casing welded to the nose portion and base portion at its opposite ends and a plurality of discrete, coaxial rings either surrounding or enclosed within the casing. The rings are not mechanically connected either to one another or to the casing so that they make little contribution to the structural integrity of the projectile.

In a modification of this prior art projectile the discrete rings are replaced by a strip wound helically onto a mandrel, cut to the required length and then inserted into the casing.

German Patent Specification No.2,215,697 discloses a projectile housing similar to the modification just referred to. Here the helically wound strip has a rectangular cross-section with bevelled corners and the strip is notched to improve fragmentation of the strip when the projectile explodes.

Projectile housings which include a helically wound strip give rise to manufacturing difficulties in ensuring that the coiled strip does not unwind prematurely before the casing is sealed to the base or, in the version of the German Specification, before an annular component of the nose portion bearing the detonator is inserted into a flared end of the casing remote from the base.

The wound strips require pre-fabrication on a mandrel and careful assembly, and in none of the prior art constructions described can the casing be dispensed with. Effectively the tubular wall of the housing is a double wall comprising the casing and a stack of rings of lengths of helically wound strip.

An anti-aircraft shell is known which comprises a tubular core containing the explosive and surrounded by a stack of steel rings extending between the base and nose portions of the shell.

The rings are held in compression by screwing up a nut which displaces the base toward the nose portion, but here again there is no mechanical connection between the steel rings and the tubular core is indispensible.

A principal object of the present invention is to provide a projectile housing of simpler but improved construction, in which the need for a tubular casing or core is eliminated and in which the rings making up the tubular wall of the housing themselves prevent mutual dislodgement and contribute to the structural stability of the projectile. The housing of the invention eliminates the need for helical winding of a strip on a mandrel and the associated difficulties of assembly and while having the advantages of prior art proposals utilising discrete rings it avoids their drawbacks, in particular the need for an extraneous means for maintaining the rings in coaxial alignment.

In accordance with the invention there is provided a projectile housing comprising a tubular wall consisting of a plurality of coaxial rings in axial end abutting relation, the rings having axially-extending formations for interengagement of adjacent rings to resist radial dislodgement of one ring relative to the adjacent ring or rings.

The axial end faces of two adjacent rings which are in abutting relation are preferably formed with inter-fitting male and female formations. These may be annular and coaxial with said rings, and said two adjacent rings may be additionally formed or provided with means for preventing relative rotation of said rings.

The said additional means may comprise circumferentially spaced pins projecting from the abutted end face of one of said rings and engaged in blind bores in the abutted end face of the other ring, or said additional means may comprise at least one key projecting from the abutted end face of one of said rings and engaged in a keyway in the abutted end face of the other ring.

The said male formation may be an annular flange extending axially from the abutted end face of one of said two rings and said female formation may be an annular rebate in the abutted end face of the other of said rings. Said flange and rebate may be at the outer peripheries of the associated rings, or at the inner peripheries of the associated rings.

Alternatively, said male formation may be an annular projection extending axially from the abutted end face of one of said two rings intermediate the inner and outer peripheries of said face and the female formation may be an annular recess in the abutted end face of the other of said two rings intermediate the inner and outer peripheries of said face. In this construction the annular projection of said one ring may be provided by half of an annular element separable from said one ring and symmetrical on opposite sides of its median plane, the abutted end face of said one ring having an annular recess, corresponding with that in said other ring, in which the other half of said annular element is received.

The projection and recess are preferably of corresponding trapezium radial cross-sectional shape so that the projection tapers toward its free end and the recess tapers toward its closed end.

Said additional means may alternatively comprise a series of circumferentially spaced, radially-extending projections on the abutted end face of one of said rings received in respective, radially-extending recesses in the abutted end face of the other ring.

In yet another embodiment of the invention said abutted end faces have similar, interdigitated radially-extending serrations. The radially inner surfaces of the ring may be so shaped that on opposite sides of a central region of the wall successive rings have inner peripheries which are progressively more steeply inclined with respect to the axis of the wall so that the inner surface of the wall has a bowed configuration in longitudinal section.

The abutting end faces of two adjacent rings are preferably adhesively secured together. The rings may have circumferentially spaced grooves in their inner peripheries to assist fragmentation of the rings.

Preferred embodiments of the invention will now be described with reference to the accompanying diagrammatic drawings, in which Figures 1 and 2 are sectional elevations of two different projectile housings in accordance with the invention, taken in planes radial to the longitudinal axis X-X of each housing, Figure 3 is a perspective view of a single ring for incorporation in another ring housing in accordance with the invention, Figure 4 is a sectional elevation of part of a ring such as is shown in Figure 3, Figure 5 is a sectional view in a radial plane of two rings forming part of yet another housing in accordance with the invention, Figure 6 is an end view of a ring showing an optional modification, Figures 7 and 8 illustrate yet another modified ring, Figure 8 being a radial section taken on the iine 8-8 of Figure 7, the latter being an end view, Figures 9 and 10 illustrate a two-part ring for incorporation in yet another modified housing, Figure 9 being an exploded view in radial section taken on the line 9-9 in Figure 10 of the twopart ring shown in end view in Figure 10, and Figure 11 is a view similar to Figure 9 of an alternative two-part ring for incorporation in yet another modified housing.

The projectile housings 10 shown in Figures 1 and 2 each comprise a base 11 and a nose portion 12 on which a detonator 13 is mounted.

Within a tubular wall between the base 11 and nose portion 12 an explosive charge 14 is located. As shown in Figure 2, an amplifier 1 6 is preferably connected to the detonator 13 by a passage 1 5 in the explosive charge 14 so that when the latter explodes an approximately spherical shock wave will expand from a point which is approximately in the middle of the charge 14.

In accordance with the invention the tubular wall of the housing 10 consists solely of rings 18, preferably of steel, which are in end-abutting, coaxial relation, their abutting surfaces being adhesively secured together, preferably by means of a heat-resistant metal adhesive of high mechanical strength. Films or foils may be used, for example of glass or other synthetic fibre reinforced phenolic resin, which bend under the application of heat or pressure.

In the embodiments of the invention shown in Figures 1, 2 and 5, each adjacent pair of rings such as 1 8a and 1 8b have axially-extending, interengaging male and female formations at their abutted end faces to prevent radial displacement of one ring relative to another. In Figures 1 and 2 one ring, such as 1 8a, has an annular flange 20 at its radially outer or inner periphery which seats in an annular rebate 19 in the radially outer or inner periphery of the adjacent ring, such as 1 8b. The dimensions of the flange and rebate are such that the opposed surfaces 1 7 of the main portions 1 9a and 20a of the rings can be brought into abutment and adhesively secured together.

In the embodiment of Figure 5 each ring such as 1 8a,1 8b is kinked axially to have parallel portions 20, 20a and 19, 1 9a perpendicular to the axis X-X an'd an intermediate portion oblique with respect to said axis providing additional surfaces 49 which will abut adjacent rings when the rings are rested together as shown.

In the embodiments so far described adjacent rings 1 8 will be capable of relative rotation (except for the action of the adhesive) and to avoid this (for example for the better transmission of spin between the components of the housing 10) Figure 6 illustrates an embodiment in which circumferentially-spaced pins 33 project axially from one end face of a ring 1 8 to be received in corresponding, blind bores in the opposite end face of an adjacent ring (not shown). The provision of the pins 33 and bores is enough alone to prevent relative radial movement of adjacent rings as well as relative rotation, but if desired the rings of Figures 1,2 and 5 may be additionally provided with such pins and bores.

Figure 3 illustrates how both radial and rotational displacement of a ring 18 may be avoided by forming radial serrations or teeth 29 and 30 in the opposite end faces 27 and 28 of the ring.

Figures 7 and 8 show a modification in which each ring 18 has an annular projection 34 on one end face and a complementary annular recess 35 in its other face, the projection and recess being equally spaced from the radially inner and outer peripheries of the ring so that the projection 34 of one ring can be received in the recess 35 of the adjacent ring. Both the projection 34 and recess 35 are of trapezium-shaped radial cross-section which facilitates moulding the ring as well as assembly.

In addition to the annular projection 34 and annular recess 35 the ring may have circumferentially spaced radially-extending projections 36 at one end face and complementary recesses 36A in its opposite face to prevent relative rotation of two adjacent rings.

If the radial projections 36 and recesses 36A are each more than two in number, as shown in Figure 7, the annular projection 34 and recess 35 may be dispensed with because the radial projections and recesses 36 and 36A will themselves resist radial dislodgement, as well as relative rotation, of two adjacent rings.

In the embodiments of the invention shown in Figures 9 and 10 and Figure 11 each ring 37 or 48 is of two-part construction. As shown in Figures 9 and 10 each ring 37 comprises a female part 38 and a male part 39, each of which is symmetrical about its median plane Y-Y. The female part 38 has complementary, trapeziumshaped annular recesses 40 and 41 in its opposite axial end faces, each of these recesses being equally spaced from the radially inner and outer peripheries 22 and 23 of part 38. The male part 39 is shaped so that when one half of it is received in the recess 41 the other half will project from the end face in which the recess 41 is formed, the median plane Y-Y of the male part 39 generally coinciding with said end face.Thus the assembled two-part ring 37 will have a trapezium-shaped projection constituted by one half of the male part 39 extending from one axial end face for engagement in the correspondinglyshaped recess 40 in one adjacent ring 37 and a trapezium-shaped recess 40 in its other axial end face to receive the projection formed by half of a part 39 of another adjacent ring 37.

As shown in Figure 10, rectangular keys 42 and 43 projecting from the inner axial face of the male part 39 may be received in correspondinglyshaped keyways, such as 42A in the female part 38 to prevent relative rotation of the male and female parts 38 and 39. Similar provision may be made for preventing relative rotation of two adjacent two-part rings 37.

The embodiment of Figure 11 differs from that of Figures 9 and 10 only in that the male component 45 of the two-part ring 48 has a central portion, between complementary trapezium-shaped annular projections 47, which is of the same internal and external diameter as the female part 44. It will be appreciated that when a projection 47 is received in one of the recesses 46 the opposed axial end faces of the two parts 44 and 45 will be in abutment and the two-part ring 48 will differ from the two-part ring 37 only by the greater axial extent represented by the axial width of the male part 45 between its projections 47.

The inner surface of the tubular wall formed by the assembled rings 18, 37 or 48 may be smooth and of generally cylindrical, or slightly oval shape as shown in Figure 1 or, as shown in Figure 2, the radially-inner surfaces of different rings making up the same wall may have a different inclination to the axis X-X which becomes progressively steeper from a central region toward the opposite ends of the wall so as to give the inner surface of the wall a bowed configuration in longitudinal section,, The effect of this arrangement is that a blast propagated centrally of the charge 14 from the amplifier 1 6 will, when it fragments the rings, propel the fragments in divergent paths as indicated by the arrows 25 and 26 in Figure 2 instead of in generally parallel paths as indicated by the arrow 24 in Figure 1.

It will be noted that in all of the embodiments of the invention described (with the exception of Figure 6, which may be regarded as an optional variant of the embodiments of Figures 1, 2 and 5) the complementary projections and recesses of adjacent rings have a tapering profile which facilitates both production and assembly of the rings. A recess may be made slightly deeper than the projection to be received therein in order to ensure close abutment between opposed axial end faces 17 of adjacent rings.

The rings 1 8 at opposite ends of the tubular wall formed thereby may be modified for screwthreaded connection respectively to the nose portion 12 and base 11 or, as shown in Figures 1 and 2, the base 11 and nose portion 12 may be shaped to receive the male or female formation on the adjacent axial end face of the adjacent ring and the tubular wall may be adhesively secured to the base and nose portions.

On detonation of the explosive charge 14 the tubular wall disintegrates, the rings 1 8 separating at their adhesively-secured surfaces 1 7 and dividing into fragments of a size and shape predetermined by the provision of longitudinal grooves 32 in the inner peripheries 31 of the rings 1 8, 37 or 48 as shown in Figure 4. The paths in which the fragments are dispersed can be predetermined by the shapes selected for the inner peripheries of the rings.

Claims

1. A projectile housing comprising a tubular wall consisting of a plurality of coaxial rings in axial end abutting relation, the rings having axially-extending formations for interengagement of adjacent rings to resist radial dislodgement of one ring relative to the adjacent ring or rings.

2. A projectile housing as claimed in claim 1, wherein the axial end faces of two adjacent rings which are in abutting relation are formed with inter-fitting male and female formations.

3. A projectile housing as claimed in claim 2, wherein said male and female formations are annular and coaxial with said rings.

4. A projectile housing as claimed in claim 3, wherein said two adjacent rings are additionally formed or provided with means for preventing relative rotation of said rings.

5. A projectile housing as claimed in claim 4, wherein said additional means comprises circumferentially spaced pins projecting from the abutted end face of one of said rings and engaged in blind bores in the abutted end face of the other ring.

6. A projectile housing as claimed in claim 4, wherein said additional means comprises at least one key projecting from the abutted end face of one of said rings and engaged in a keyway in the abutted end face of the other ring.

7. A projectile housing as claimed in any one of claims 3-6, wherein said male formation is an annular flange extending axially from the abutted end face of one of said two rings and said female formation is an annular rebate in the abutted end face of the other of said rings.

8. A projectile housing as claimed in claim 7, wherein said flange and rebate are at the outer peripheries of the associated rings.

9. A projectile housing as claimed in claim 7, wherein said flange and rebate are at the inner peripheries of the associated rings.

10. A projectile housing as claimed in any one of claims 3-6, wherein said male formation is an annular projection extending axially from the abutted end face of one of said two rings intermediate the inner and outer peripheries of said face and the female formation is an annular recess in the abutted end face of the other of said two rings intermediate the inner and outer peripheries of said face.

11. A projectile housing as claimed in claim 10, wherein the annular projection of said one ring is provided by half of an annular element separable from said one ring and symmetrical on opposite sides of its median plane, the abutted end face of said one ring having an annular recess, corresponding with that in said other ring, in which the other half of said annular element is received.

12. A projectile housing as claimed in claim 10, or claim 11, wherein the projection and recess are of corresponding trapezium radial cross-sectional shape so that the projection tapers toward its free end and the recess tapers toward its closed end.

13. A projectile housing as claimed in claim 4, wherein said additional means comprises a series of circumferentially spaced, radially-extending projections on the abutted end face of one of said rings received in respective, radially-extending recesses in the abutted end face of the other ring.

14. A projectile housing as claimed in claim 2, wherein said abutted end faces have similar, inter-digitated radially-extending serrations.

1 5. A projectile housing as claimed in any one of the preceding claims, wherein the radially inner surfaces of the rings are so shaped that on opposite sides of a central region of the wall successive rings have inner peripheries which are progressively more steeply inclined with respect to the axis of the wall so that the inner surface of the wall has a bowed configuration in longitudinal section.

1 6. A projectile housing as claimed in any one of the preceding claims wherein the abutting end faces of two adjacent rings are adhesively secured together.

17. A projectile housing as claimed in any one of the preceding claims wherein the rings have circumferentially-spaced grooves in their inner peripheries to assist fragmentation of the rings.

1 8. A projectile housing substantially as herein described with reference to and as illustrated in Figure 1, Figure 2, Figures 3 and 4, Figure 5, Figures 6-8, Figures 9 and 10 or Figure 11 of the accompanying drawings.