Improvements in or relating to command initiated fragmentation charges

Abstract

A projectile for a command-initiated fragmenting charge, having a front surface and a rear surface defining a volume, the volume contains a plurality of projectile elements, in which the front surface and / or the rear surface is a hyperbolic paraboloid.

Description

[0001] The present invention relates generally to explosively driven charges and particularly, although not exclusively, to directional fragmentation projectiles and charges.

[0002] The Claymore is a directional fragmentation charge developed for the United States Armed Forces. Unlike a conventional land mine, the Claymore is command-detonated and directional, meaning it is fired by remote-control and shoots a wide pattern of metal balls.

[0003] Known fragmentation charges typically have a horizontally convex plastic case. The shape was developed to deliver the optimum distribution of fragments at 50 metre range. Internally the charge contains explosive material behind a matrix of steel balls set into an epoxy resin. When the charge is detonated, the explosion drives the matrix forward out of the charge, at the same time breaking it into individual fragments. The steel balls are projected in a 60° fan-shaped pattern that is 2.0 metres high and 50 m wide at a range of 50 m.

[0004] The present invention seeks to provide improvements in or relating to command-initiated directional fragmentation charges.

[0005] The present invention relates to command-initiated devices that are not landmines in accordance with the UK Landmines Act 1998.

[0006] An aspect of the present invention provides a projectile for a command-initiated fragmenting charge, having a front surface and a rear surface defining a volume, the volume contains a plurality of projectile elements, in which the front surface and / or the rear surface is a hyperbolic paraboloid.

[0007] The volume may be defined by a projectile body or casing with a sidewall between the front and rear surfaces.

[0008] The front surface and the back surface may be substantially parallel to each other.

[0009] In some embodiments one of the front surface and the back surface is generally flat.

[0010] In some embodiments a projectile body is provided and comprise a pot.

[0011] A projectile body may comprise a cover.

[0012] The hyperbolic paraboloid may be generally circular and has a diameter to height ratio in the range 5:1 and 20:1.

[0013] The hyperbolic paraboloid may be generally rectangular and has a width to height ratio of between 1:2 and 1:13.

[0014] Projectile elements may be arranged in one or more layers.

[0015] In some embodiments a plurality of layers of projectiles are separated by lamina.

[0016] Some embodiments provide a plurality of layers and projectiles in successive layers are axially aligned.

[0017] Some embodiments provide a plurality of layers and projectiles in successive layers are axially misaligned.

[0018] The or each layer may be a hyperbolic paraboloid.

[0019] Some embodiments comprise a hyperbolic paraboloid wave shaper for directing projectiles.

[0020] Projectile elements may, for example, be generally spherical or generally cuboidal.

[0021] Projectile elements may be formed from one or more of: steel, tungsten carbide, aluminium, incendiary material.

[0022] The present invention also provides a command-initiated directional fragmentation device comprising a projectile as described herein and an explosive charge.

[0023] The charge may comprise explosive material that is generally parallel to the projectile.

[0024] Explosive material may be in intimate contact with a projectile.

[0025] The explosive charge may be provided in an explosive charge housing.

[0026] The present invention also provides a charge as described herein in combination with an automated pan-tilt system.

[0027] Tracking and / or aiming means may be provided.

[0028] An aspect of the present invention provides a fragmenting projectile body, the body can receive a plurality of projectile elements, in which a front wall and / or a rear wall is a hyperbolic paraboloid.

[0029] The term “front” may refer to a direction in which the projectile operates in use e.g. forward facing.

[0030] In some aspects and embodiments a fragmenting projectile is provided or can be placed in a charge body and / or can be backed by explosive material.

[0031] In some aspects and embodiments explosive material is or can be loaded into the body.

[0032] A hyperbolic paraboloid is a doubly-curved surface that resembles the shape of a saddle; that is, it has a convex form along one axis, and a concave form on along the other. It is also a doubly-ruled surface i.e. every point on its surface lies on two straight lines across the surface. Horizontal sections taken through the surface are hyperbolic in format and vertical sections are parabolic.

[0033] The body may comprise a back wall, the front wall and back wall being mutually spaced.

[0034] The front wall and back wall may be substantially parallel to each other. Alternatively the walls may be non-parallel. For example the back wall may be generally flat, or the front and back walls may both be hyperbolic paraboloids but with different curvatures.

[0035] In some embodiments a sidewall extends from the front wall and / or back wall.

[0036] The body may be formed as a pot and a cover. A pot may be formed by a back / rear wall with an upstanding sidewall. The front wall may be configured to provide a cover.

[0037] The front wall may comprise an upstanding sidewall, which could for example provide a flat face.

[0038] The body may be generally round.

[0039] The body may be relatively shallow in depth, for example relatively shallow in depth from a front wall to a back wall.

[0040] Projectile elements may be arranged in one or more layers.

[0041] The or each layer may be a hyperbolic paraboloid.

[0042] Some embodiments include a plurality of layers. A separator may be provided between layers, for example formed from a plastics material, Mylar (RTM) or foil.

[0043] Projectile elements may be generally spherical or generally cuboidal, for example.

[0044] Projectile elements may be formed from one or more of: steel, tungsten carbide, aluminium, incendiary material.

[0045] The body may comprise means for receiving an initiator, for example a detonator well.

[0046] The hyperbolic paraboloid (of walls and / or projectile layers) may have a diameter to height ratio in the range 10:1 and 3:1.

[0047] Hyperbolic paraboloids of parts of the body and / or charge may have a width to height ratio of between approximately 1:2 and 1:13.

[0048] Some embodiments may comprise one or more of the following features.

[0049] Overall shape may be a 3D / extruded hyperbolic paraboloid.

[0050] Cross section may be generally circular, elliptical, round or mostly round, or square.

[0051] Linear.

[0052] Approximately I:I height to width.

[0053] Can have a different sized hyperbolic paraboloid on the front and back face (i.e. more or less curved).

[0054] The hyperbolic paraboloids may have a Width (W) to Height (H) ratio of between 1:2 and 1:13.

[0055] The thickness of the projectile may be determined by the size of BBs / preformed fragments and the number of layers of BB / preformed fragments.

[0056] The internal profile of the projectile may allow for containment of a raft of ball bearings / pre-formed fragments.

[0057] Controlled detonation may be accomplished by use of either an electrical or non-electrical firing system, for example.

[0058] A further aspect provides a directional fragmentation device comprising a body, a plurality of projectile elements are provided in the body, in which the projectile elements are arranged in a generally hyperbolic paraboloid assembly.

[0059] A further aspect provides a directional fragmentation device comprising a plurality of projectiles pre-formed in a generally hyperbolic paraboloid shape assembly.

[0060] A hyperbolic paraboloid raft of projectiles (with or without a case) could be provided, for example.

[0061] Embodiments with a case may have a front and / or rear face. The face / s may themselves have a generally hyperbolic paraboloid form, but not necessarily.

[0062] Some aspects and embodiments may be configured to control projectile spread in one axis (“axially confined”).

[0063] Further aspects and embodiments are listed in the following numbered paragraphs.

[0064] 1. A command-initiated fragmenting projectile body having a front wall, the body can receive a plurality of projectile elements, in which the front wall is a hyperbolic paraboloid.

[0065] 2. A command-initiated fragmenting projectile comprising a body having a front wall, a plurality of projectile elements are provided in the body, in which the front wall is a hyperbolic paraboloid.

[0066] 3. A body or projectile of paragraph I or paragraph 2, in which the body further comprises a back wall, the front wall and back wall being mutually spaced.

[0067] 4. A body or projectile of paragraph 3, in which the front wall and back wall are substantially parallel to each other.

[0068] 5. A body or projectile of paragraph 3, in which the back wall is generally flat.

[0069] 6. A body or projectile of any of paragraphs 3 to 5, in which a sidewall extends from the front wall and / or back wall.

[0070] 7. A body or projectile of any preceding paragraph, in which the body comprises a pot and a cover.

[0071] 8. A body or projectile of paragraph 7, in which the front wall is the cover.

[0072] 9. A body or projectile of any preceding paragraph, in which the body is generally round.

[0073] 10. A body or projectile of any preceding paragraph, in which the body is relatively shallow in depth.

[0074] 11. A body or projectile of any preceding paragraph, in which projectile elements are arranged in one or more layers.

[0075] 12. A body or projectile of claim II, in which the or each layer is a hyperbolic paraboloid.

[0076] 13. A body or projectile of any preceding paragraph, in which the projectile elements are generally spherical.

[0077] 14. A body or projectile of any preceding paragraph, in which projectile elements are formed from one or more of: steel, tungsten carbide, aluminium, incendiary material.

[0078] 15. A body or projectile of any preceding paragraph, in which the hyperbolic paraboloid has a diameter to height ratio in the range 10:1 and 3:1.

[0079] 16. A body or projectile of any preceding paragraph, in which the hyperbolic paraboloid has a width to height ratio of between 1:2 and 1:13.

[0080] 17. A command-initiated directional fragmentation device comprising a body, a plurality of explosively projectable elements are provided in the body, in which the projectable elements are arranged in a generally hyperbolic paraboloid assembly.

[0081] 18. A command-initiated directional fragmentation device comprising a plurality of projectiles pre-formed in a generally hyperbolic paraboloid shape assembly.

[0082] 19. A device of paragraph 18, in which the projectiles are housed in a case.

[0083] 20. A device of paragraph 19, in which the case includes a front face which is a hyperbolic paraboloid shape.

[0084] 21. A body, charge or device of any preceding paragraph in combination with an explosive material charge for controlled detonation for driving elements out of the body.

[0085] 22. A command-initiated fragmentation charge body having a front wall, the body can receive a plurality of projectile elements and explosive material for driving the elements out of the body upon detonation, in which the front wall is a hyperbolic paraboloid.

[0086] Aspects and embodiments of the present invention are designed / configured / adapted to be command-initiated.

[0087] Different aspects and embodiments of the invention may be used separately or together.

[0088] Further particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with the features of the independent claims as appropriate, and in combination other than those explicitly set out in the claims. Each aspect can be carried out independently of the other aspects or in combination with one or more of the other aspects.

[0089] The example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternative forms and should not be construed as limited to the examples set forth herein.

[0090] Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

[0091] Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealised or overly formal sense unless expressly so defined herein.

[0092] In the following description, all orientational terms, such as upper, lower, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention.

[0093] The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings.

[0094] The example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternative forms and should not be construed as limited to the examples set forth herein.

[0095] Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

[0096] Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealised or overly formal sense unless expressly so defined herein.

[0097] In the following description, all orientational terms, such as upper, lower, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention.

[0098] Referring first to Figure I there is shown a fragmenting projectile generally indicated 10.

[0099] The projectile 10 comprises case including a pot 15 and a cover 20. The pot 15 comprises a rear wall 25 with a sidewall 30 depending from the periphery thereof. The cover comprises a front wall 35.

[0100] The rear 25 and front 35 walls are generally disc-shaped, formed as hyperbolic paraboloids. In this embodiment the walls are generally parallel to each other.

[0101] FIG. 2 is an exploded view of the projectile 10, with the cover 20 shown separated from the pot 15. Within the interior of the charge are two (in this embodiment) projectile element layers 40, 45. Each layer 40, 45 comprises a plurality of projectile elements 50, which in this embodiment comprise generally spherical steel balls. The layers are formed as matrices, with the elements set into epoxy resin. The layers 40, 45 are parallel to each other and also to the walls 25, 35 in this embodiment.

[0102] FIG. 3 is a plan view of the (empty) pot and FIG. 4 is a plan view showing the layers loaded into the pot 15. FIG. 5 is a sectional view with the layers installed.

[0103] FIGS. 6 and 7 are sectional views of the filled projectile pot.

[0104] In use the fragmenting projectile can be backed by explosive material which, when detonated, drives the projectile elements out of the body / case / pot.

[0105] FIGS. 8 and 9 illustrate a comparison of projectile element spread patterns between a fragmenting projectile formed in accordance with the present invention (FIG. 9) and a projectile formed without a hyperbolic paraboloid form (FIG. 8). FIG. 8 shows a generally shotgun pattern, with a symmetrical but centralised circular pattern. Whereas the present invention provides a linear spread pattern.

[0106] FIG. 10 shows a pot 115 and cover 120 formed according to a further embodiment. An exploded view of the charge 110 is shown in FIG. 11. In this embodiment the cover 120 is provided with an upstanding skirt 155 that provides a flat terminal face.

[0107] FIGS. 12 and 13 illustrate the dimensions of a hyperbolic paraboloid that can form the basis of the present invention.

[0108] Examples of hyperbolic paraboloids are shown in FIG. 14A-D.

[0109] The paraboloids are made by sketches on two perpendicular planes: circle on one plane; parabola on the other. The circle is projected onto the parabola to create a hyperbolic parabola. When defining diameter and height the parabola focus is automatic.

[0110] The projectile elements (bb) size is 5.56 mm in this example.

[0111] Circle Diameter—97 mm,

[0112] Parabola Height—15 mm, Parabola focus-39.2 mm.

[0113] With height 30 mm, parabola focus now at 19.6 mm.

[0114] With 7.5 mm height, parabola focus 78.41.

[0115] With height 45 mm, parabola focus 13.07 mm.

[0116] During experimentation the line of BBs got more defined as height increased.

[0117] Further examples are shown in FIG. 15A-F, in this case using a circle diameter of 149.5 mm. The projectile elements (BB) size is 5.56 mm in this example.

[0118] Testing showed that hyperbolic paraboloids with a diameter to height ratio in the range 13:1 and 2:1 are possible, for example between 10:1 and 3:1.

[0119] FIGS. 16A and 16B are two examples of definitions for fragmenting projectiles formed in accordance with the present invention.

[0120] FIG. 17 show and exploded view and assembled view of a fragmenting projectile in a charge body. Explosive material can be provided in the body.

[0121] FIG. 18 shows a section of part of a projectile “raft”, with two rows (layers) 140, 145 of projectiles arranged one above the other. Projectiles 150 in a row are axially aligned with the projectiles in the other row.

[0122] FIG. 19 is similar to FIG. 18 except that the rows 240, 245 of projectiles 250 are spaced by a layer / lamina 260.

[0123] In FIG. 20 two rows 340, 345 of projectiles are again shown. In this embodiment the rows are offset.

[0124] In FIG. 21 two spaced rows 440, 445 of projectiles are shown. In this embodiment channels / rails / straws 460 or the like (e.g. tubes) are provided and receive the projectiles.

[0125] In FIG. 22 an array of projectiles 550 is shown in plan. Successive rows (in plan) are offset. In FIG. 23 a similar array of projectiles is shown, with projectiles 650 in successive rows being aligned.

[0126] Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A projectile for a command-initiated fragmenting charge, having a front surface and a rear surface defining a volume, the volume contains a plurality of projectile elements, in which the front surface and / or the rear surface is a hyperbolic paraboloid.

2. The projectile as claimed in claim 1, in which the volume is defined by a projectile body or casing with a sidewall between the front and rear surfaces.

3. The projectile as claimed in claim 1, in which the front surface and the back surface are substantially parallel to each other.

4. The projectile as claimed in claim 1, in which the one of the front surface and the back surface is generally flat.

5. The projectile as claimed in claim 1, in which a projectile body comprises a pot.

6. The projectile as claimed in claim 1, in which a projectile body comprises a cover.

7. The projectile as claimed in claim 1, in which the hyperbolic paraboloid is generally circular and has a diameter to height ratio in the range 5:1 and 20:1.

8. The projectile as claimed in claim 1, in which the hyperbolic paraboloid is generally rectangular and has a width to height ratio of between 1:2 and 1:13.

9. The projectile as claimed in claim 1, in which projectile elements are arranged in one or more layers.

10. The projectile as claimed in claim 1, comprising a plurality of layers of projectiles separated by a lamina.

11. The projectile as claimed in claim 1, comprising a plurality of layers and in which projectiles in successive layers are axially aligned.

12. The projectile as claimed in claim 1, comprising a plurality of layers and in which projectiles in successive layers are axially misaligned.

13. The projectile as claimed in claim 9, in which each of the one or more layers is a hyperbolic paraboloid.

14. The projectile as claimed in claim 1, comprising a hyperbolic paraboloid wave shaper for directing projectiles.

15. The projectile as claimed in claim 1, in which the projectile elements are generally spherical or generally cuboidal.

16. The projectile as claimed in claim 1, in which projectile elements are formed from one or more of: steel, tungsten carbide, aluminum, or incendiary material.

17. A command-initiated directional fragmentation device comprising the projectile as claimed in claim 1 and an explosive charge.

18. The device as claimed in claim 17, in which the charge comprises explosive material that is parallel to the projectile.

19. The device as claimed in claim 18, in which the explosive material is in intimate contact with the projectile.

20. The device as claimed in claim 18, in which the explosive charge is provided in an explosive charge housing.

21. The projectile as claimed in claim 1, in combination with an automated pan-tilt system.

22. The projectile as claimed in claim 21, further comprising tracking and aiming means.

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