阅读说明：本技术 爆轰波阵面控制器 (Detonation wavefront controller ) 是由 安德鲁·拉姆利 于 2019-08-06 设计创作，主要内容包括：一种用于线型聚能装药装置的爆轰波阵面控制器,所述爆轰波阵面控制器包括第一部件和第二部件。所述第一部件包括：引爆器保持器,以及第一孔,所述第一孔具有第一宽度和基本上为环状多边形、基本上为椭圆形、或基本上为圆形的形状。所述第二部件包括：第二孔,所述第二孔具有大于所述第一宽度的第二宽度。在所述第一部件至少部分地接收在所述第二部件内的情况下,所述第一部件可相对于所述第二部件移动以至少在以下各项之间构造所述爆轰波阵面控制器：在所述第一孔和所述第二孔之间具有第一距离的第一构型,以及在所述第一孔和所述第二孔之间具有第二距离的第二构型,所述第二距离大于所述第一距离。(A detonation wavefront controller for a linear shaped charge, the detonation wavefront controller comprising a first component and a second component. The first member includes: a detonator retainer, and a first bore having a first width and a shape that is substantially an annular polygon, a substantially oval, or a substantially circular. The second member includes: a second aperture having a second width greater than the first width. With the first component at least partially received within the second component, the first component is movable relative to the second component to configure the detonation wavefront controller between at least: a first configuration having a first distance between the first and second apertures, and a second configuration having a second distance between the first and second apertures, the second distance being greater than the first distance.)

1. A detonation wavefront controller for a linear shaped charge, comprising:

a first component, the first component comprising:

initiator holder, and

a first aperture having a first width and a substantially annular polygonal, substantially elliptical, or substantially circular shape; and

a second component, the second component comprising:

a second aperture having a second width greater than the first width,

wherein with the first component at least partially received within the second component, the first component is movable relative to the second component to configure the detonation wavefront controller between at least:

a first configuration having a first distance between the first aperture and the second aperture, an

A second configuration having a second distance between the first aperture and the second aperture, the second distance being greater than the first distance.

2. The detonation wavefront controller of claim 1, wherein in the first configuration the first aperture and the second aperture each lie within substantially the same plane.

3. The detonation wavefront controller of claim 1, wherein the first aperture is located at an end of the first component such that in the second configuration the first aperture is closer to the second aperture than the initiator holder.

4. The detonation wavefront controller of any of the preceding claims, wherein the detonator retainer comprises a plurality of elements for engaging an outer surface of a detonator.

5. The detonation wavefront controller of claim 4, the plurality of elements each being biased inwardly.

6. The detonation wavefront controller of claim 4, the plurality of elements comprising:

a first pair of inwardly biased elements substantially opposite each other and separated from each other by a first minimum separation in the absence of the detonator; and

a second pair of inwardly biased elements substantially opposite each other and separated from each other by a second minimum separation, less than the first minimum separation, in the absence of the detonator.

7. The detonation wavefront controller of any of the preceding claims, comprising a second component contact surface positioned to stop movement of the second component relative to the first component beyond the second component contact surface to determine the first configuration of the detonation wavefront controller.

8. The detonation wavefront controller of any of the preceding claims, the outer surface of the first component at least partially engaging the inner surface of the second component.

9. The detonation wavefront controller of claim 8, the outer surface including a plurality of protrusions and the inner surface including a plurality of recesses engageable with the plurality of protrusions.

10. The detonation wavefront controller of claim 9, wherein the plurality of protrusions includes a plurality of circumferential ridges and the plurality of recesses includes a plurality of circumferential grooves.

11. The detonation wavefront controller of any of the preceding claims, the second component including a plurality of prongs extending in a direction away from the first and second apertures.

12. The detonation wavefront controller of any of the preceding claims, the second component including a plurality of tabs extending outwardly therefrom.

13. The detonation wavefront controller of claim 12, wherein at least one of the plurality of tabs is hingeable.

14. The detonation wavefront controller of claim 12 or 13, wherein at least one tab of the plurality of tabs is foldable.

15. The detonation wavefront controller of any of the preceding claims, the wall of the second component including a plurality of wall apertures.

16. The detonation wavefront controller of claim 15, the plurality of wall apertures including a first pair of wall apertures opposite one another and a second pair of opposite wall apertures opposite one another.

17. The detonation wavefront controller of claim 15 or 16, wherein at least one wall aperture of the plurality of wall apertures narrows toward the second aperture.

18. The detonation wavefront controller of any of the preceding claims, wherein the second width is at least three times the first width.

19. The detonation wavefront controller of any of the preceding claims, wherein the first aperture and the second aperture are each substantially circular, and the first width is a first diameter and the second width is a second diameter.

20. The detonation wavefront controller of any of the preceding claims, wherein in a third configuration, the detonation wavefront controller includes a third component comprising:

a third aperture having a third width greater than the second width, an

A third distance between the first and third apertures.

21. The detonation wavefront controller of claim 20, the third member engageable with the second member to at least partially receive the second member to position the third aperture at the third distance between the third aperture and the first aperture.

22. The detonation wavefront controller of any one of claims 20 to 21, wherein in the third configuration the first, second and third apertures each correspond to a respective cross-sectional profile of a predetermined conical or frustoconical shape taken at a different plane.

23. The detonation wavefront controller of any of claims 20 to 22, wherein the third aperture is substantially circular and the third width is a third diameter.

24. A kit, comprising:

a first component as claimed in any one of the preceding claims;

a second component according to any preceding claim separate from and engageable with the first component to assemble a detonation wavefront controller according to any of claims 1 to 19, and optionally:

a third component of any one of claims 20 to 23 separate from and engageable with the first and second components to assemble the detonation wavefront controller of any one of claims 20 to 23; or

A linear shaped charge comprising a housing including a third part as claimed in any one of claims 20 to 23 engageable with the second part to assemble a detonation wavefront controller as claimed in any one of claims 20 to 23.

25. A linear shaped charge comprising a part configured to engage with the second part of any of claims 1 to 19, wherein optionally the part configured to engage with the second part is the third part of any of claims 20 to 23.

Background

Linear shaped charges (linear shaped charges) may be detonated, for example, by using a detonator inserted into the explosive bed of the charge. However, standard detonators are not always suitable for the specific cutting task performed by a linear shaped charge.

It is desirable to improve the detonation of linear shaped charges.

Drawings

FIG. 1 schematically illustrates a Detonation Wavefront Controller (DWC) in a first configuration, according to an example;

FIG. 2 shows the DWC of FIG. 1 in a second configuration;

figures 3a to 3e show various views of a first component of the DWC of figure 1;

figures 4a to 4e show various views of a second component of the DWC of figure 1;

figures 5, 6 and 7 show the use of a DWC with a linear shaped charge;

figure 8 shows the DWC of figure 1 with a third component according to an example;

fig. 9a to 9d show various views of such a third component;

FIGS. 10, 11 and 12 illustrate various uses of a DWC with a detonating cord; and

figures 13 and 14 show an exemplary linear shaped charge for use with a DWC.

Detailed Description

Conventional detonators, such as the so-called L2a2 detonator (available from Chemring engergetics UK, Troon House, arder Site, Stevenson, Ayrshire KA203LN, Scotland, UK) or the so-called TE-transient electric detonators (available from Orica,1 nicholoson Street, East Melbourne, Victoria 3002, Australia), can output detonation waves with a predetermined form upon detonation. The detonation wavefront is determined by the configuration of the detonator itself. However, due to the longitudinal shape of the linear shaped charge igniting the longitudinal cutting jet at the target, rather than the so-called point shaped charge igniting at a non-longitudinal point on the target, it has been realized that the ignition behavior of the linear shaped charge can be adjusted for a given task by controlling the form of the detonation wave front.

One option for giving more control over the wavefront form is to provide different detonators that output detonation wavefronts of different shapes. However, this is not practical where a linear shaped charge is typically used. For example, in remote locations it may be simpler to keep a batch of identical detonators with identical detonation properties to ensure that no errors occur in selecting the correct detonator, which could otherwise result in a compromised or unpredictable firing of the linear shaped charge.

The exemplary insight herein is to control the detonation wavefront output by the detonator such that a desired detonation wavefront can be selected or more closely obtained for a desired firing behavior of the linear shaped charge. In this manner, using the example detonation wavefront controllers described herein, a user may control the form of the detonation wavefront of the explosive input to the linear shaped charge to optimize the performance of the linear shaped charge for a given cutting task. For example, as explained below, the proportion of explosive energy directed towards the target (e.g. directed in a plane coincident with the longitudinal axis of the linear shaped charge, the plane including the apex of the liner (described below) and intersecting the surface of the linear shaped charge to contact the target) may be controlled compared to the proportion of explosive energy directed along the length of the linear shaped charge.

A detonator is a device for triggering detonation or detonation of explosive material, such as the explosive material of a linear shaped charge. Typically, an electrical signal is used to trigger detonation, which detonates (e.g. initiates combustion of) the primary explosive material, which in turn outputs sufficient energy from the detonator to cause detonation of the explosive material of the linear shaped charge. Accordingly, the explosive material of the linear shaped charge may be referred to as a secondary explosive.

The energy output from the detonation of the detonator may be considered to be in the form of a detonation or shock wave. The wavefront of such a wave has a shape or form that depends on factors such as: the rate of release of energy from the explosive material upon detonation, and the degree of spatial uniformity of the energy released by the explosive material upon detonation. Another factor is whether the wavefront encounters any structure that may change the shape or form of the wavefront as it propagates. One of more such structures may, for example, absorb, reflect, redirect, or diffract at least a portion of a wavefront. In this way, the curvature of the wave fronts, the spacing between successive wave fronts and/or the propagation velocity of the wave fronts can be determined.

An example of a detonation wavefront controller will now be described. Although the same type of detonator is used, such a controller may be configured between different configurations that each result in the output of a detonation wavefront having a different waveform. This gives the user the flexibility to select or "dial in" a desired detonation wavefront to detonate the linear shaped charge. In an example, the detonation wavefront controller may be provided separately from the linear shaped charge for insertion into the explosive material of the linear shaped charge. In other examples, it is contemplated that a linear shaped charge may be manufactured using the detonation wavefront controller already provided, for example as an integral component of the linear shaped charge. In an alternative example, the detonation wavefront controller may be provided with a detonator; for example, the detonator may be integrally formed as part of the detonation wavefront controller.

Examples are described herein with respect to a first aperture of a first component.

Fig. 1 and 2 each schematically show a side view of a detonation wavefront controller 2 (referred to elsewhere herein as a DWC) according to an example. Fig. 1 shows the DWC in a first configuration, and fig. 2 shows the DWC in a second configuration. In the first configuration, the first component 4 of the DWC is at least partially received within the second component 6. The first configuration may be considered a collapsed or unstretched state, and the second configuration may be considered an uncollapsed or stretched state. In some examples, the DWC may be considered to have a telescoping function where the first and second members are concentric with one another and their movement relative to one another is sliding toward or away from one another to collapse or extend the DWC, for example, where the first and second members are cylindrical or tubular.

The first component will now be described in further detail using fig. 3a to 3e, which schematically show the first component in a side view, a perspective view, a sectional view, a top view and a bottom view, respectively. The second component is then described in further detail using fig. 4a to 4e, which schematically show the second component in side view, perspective view, sectional view, bottom view and top view, respectively. Note that for clarity, fig. 3a to 4e show the first and second components separated from each other, however, as shown in fig. 1 and 2, the DWC has the first component engaged with the second component, as will be explained later.

The first component is a hollow element, such as a tube or tubular structure, whose cross-section (taken perpendicular to the longitudinal axis LA) may be circular, and thus cylindrical in shape. However, it should be understood that other cross-sectional shapes are possible. The first component includes an initiator holder configured to hold an initiator. Although the detonator can be configured to hold one particular type of conventional detonator, in other examples such as that shown, the detonator retainer is configured to hold different types of detonators, such as those having different widths. As shown in fig. 3a to 3e, the detonator retainer comprises a plurality of elements 8 for engaging with the outer surface of the detonator. Two or more such elements may be present. In the example shown, there are two pairs of such elements; a first pair 8a substantially opposite (within acceptable manufacturing tolerances) to each other, and a second pair 8b substantially opposite (within acceptable manufacturing tolerances) to each other. Each such element may be a moulding of the first part, such as an arm or tab, which extends inwardly into a hollow or cavity within the first part. Each element may be biased inwardly such that when engaged with an outer surface of the detonator, they exert an inward force against the detonator to grip the detonator and thereby hold the detonator in place. Two or more such elements will be sufficient to retain the detonator. With the first and second pairs 8a, 8b, the detonator retainer is configured to retain detonators having a greater range of widths. For example, in the absence of an initiator, a first pair of inwardly biased elements are separated from each other by a first minimum separation 10, and a second pair of inwardly biased elements are separated from each other by a second minimum separation 12, taken in the same plane as the first minimum separation 10 and less than the first minimum separation. Thus, the first pair of elements can accommodate a wider detonator and the second pair of elements can accommodate a narrower detonator. Figure 3c shows an exemplary initiator 14, shown in phantom, inserted through a hole 16 at one end 18 of the first component and retained within the hollow of the first component by an initiator retainer. The degree of insertion of the detonation wavefront controller may be determined by the user; in some examples, the end of the detonator is in the same plane as the bore 22 so as to be flush with the bore, while in other examples the end of the detonator may be inserted to a lesser extent to leave a space (between the bore 22 and the end of the detonator) that is filled with explosive material (such as a projectile as described below). If inserted to a lesser extent, the inner surface of the first component can be configured, for example, positioned, shaped, and/or sized to at least partially shape the detonation wavefront output by the detonator and to at least partially shape the detonation wavefront as it propagates through the remainder of the first component.

At the second end 20 of the first component, there is an aperture 22 (referred to herein elsewhere as the first aperture) which is an opening for outputting a detonation wavefront emitted from the detonator. The width W1 of the first aperture (referred to herein elsewhere as the first width) is determined, for example, by the thickness T of at least a portion of the wall 24 of the first component surrounding the hollow of the first component. In the example shown, the portion 26 of the wall 24 has a constant thickness between the second end 20 and the initiator holder within acceptable manufacturing tolerances. In other examples, the thickness of the portion 26 of the wall may vary along the length of the DWC (corresponding to the longitudinal axis LA). The first aperture is, for example, circular, wherein the width W1 is a first diameter. Thus, in some examples, the shape of the inner surface of the portion 26 of the wall 24 may be cylindrical, but in other examples may be a different shape, such as conical or frustoconical (where the cone widens, e.g., toward the first aperture) to help modify the detonation wavefront output by the detonator and modify the detonation wavefront before output through the first aperture 22.

The first member is configured to engage the second member such that the first and second members are movable relative to each other to change the configuration of the DWC. The outer surface of the first member may be configured to at least partially engage and effect such movement relative to the inner surface of the second member, and also provide sufficient friction or other contact or resistance against the second member to maintain the DWC in a particular configuration once the first and second members have moved to a position for that configuration. For example, the outer surface of the first component includes one or more protrusions for engaging with corresponding structures (such as one or more recesses of the inner surface of the second component). Such one or more protrusions may be distributed longitudinally along the first component in a direction parallel to the longitudinal axis LA, and may be circumferential ridges 27 each at least partially around a circumference of the first component in a respective plane taken perpendicular to the longitudinal axis LA.

The end 18 of the first component opposite the end of the first aperture may be configured to assist a user in gripping the first component and moving it relative to the second component. For example, the portion 28 of the first component may be enlarged, e.g. wider, e.g. with a larger diameter, than a different portion which is narrower than the wider portion. The wider portion can be grasped by a user to push the first component into or pull it out of the second component, with a different narrower portion sized to be received within the hollow of the second component. The outer surface of the wider portion 28 may be contoured or otherwise configured to enhance a user's grip, for example, with circumferential grooves or depressions.

In the case where the first component widens between the narrower different portion and the wider portion 28, there may be a surface connecting the outer surfaces of the two portions. This surface is referred to herein as, for example, the second component contact surface 30, and is, for example, an annular surface positioned to inhibit movement of the second component relative to the first component beyond the second component contact surface. In this way, for the first configuration, the position of the first component relative to the second component is determined by the position of the second component contacting surface 30, as the second component cannot move to further collapse the DWC when in contact with surface 30.

The second component will now be described with reference to fig. 4a to 4 e.

The second component comprises a hollow element, such as a tube or tubular structure, whose cross-section (taken perpendicular to the longitudinal axis LA) may be circular, and thus cylindrical in shape. Other cross-sectional shapes corresponding to the cross-sectional shape of the first component are contemplated. The second component is configured to receive the first component at least partially within a hollow or cavity within the second component. Thus, the cross-sectional diameter of the inner surface of the second component is larger than the cross-sectional diameter of the outer surface of the portion of the first component for receipt within the second component. Thus, the first component may be at least partially inserted into the second component until, in a suitable example, the second component contacts the second component contact surface 30.

The first component may be inserted into the second component through the aperture 32 at one end 34 of the second component. The shape of the hole corresponds to the cross-sectional shape of the inner surface of the part of the first part that is insertable into the second part. Thus, the aperture may be circular. An inner surface of a portion of the second member, such as at end 34 having aperture 32 receiving the first member, may be configured to effect movement relative to an outer surface of the first member received within the second member, and also to provide sufficient friction or other contact or resistance against the first member to maintain the DWC in a particular configuration. For example, the inner surface of the portion of the second component may comprise one or more recesses for engagement with corresponding structures (such as the one or more protrusions of the first component described above). Such one or more depressions may be longitudinally distributed along the portion of the second component in a direction parallel to the longitudinal axis LA, and may be circumferential depressions 36 that each at least partially correspond with a circumference of an inner surface of the portion of the second component taken perpendicular to the longitudinal axis LA.

The second component includes a hole 38 (referred to elsewhere herein as a second hole), for example, at an end 40 of the second component opposite the end 34. The width W2 (referred to elsewhere as the second width) of the second aperture 38 is greater than the first width W1 described above. Similar to the first aperture, the second aperture may be circular, with the second width W2 being the second diameter.

As shown in fig. 1 and 2, the DWC may be configured in either the first configuration or the second configuration depending on the position of the first component relative to the second component. Thus, the distance between the first and second apertures 22, 38 may be varied by collapsing or uncollapsed the DWC. In the first configuration, a first distance D1 (not shown, as explained below) is assumed between first aperture 22 and second aperture 38, and in the second configuration, a second distance D2 is assumed between first aperture 22 and second aperture 38. The first distance D1 and the second distance D2 are each taken in a direction parallel to the longitudinal axis LA.

In the second configuration, the second distance D2 is greater than the first distance D1. Thus, in the first configuration, the first distance D1 is less than the second distance D2. In some examples (such as those shown), in the first configuration, the first component may be positioned such that the first and second bores 22, 38 each lie in substantially (e.g., within +/-1 millimeter) the same plane (taken perpendicular to the longitudinal axis LA). In the second configuration, the first bore 22 is closer to the second bore 38 than the initiator holder.

In some examples, the second member is configured to be attached to a linear shaped charge. For example, the second part may comprise one or more pointed tips 42, which may be considered spikes, pointed elements or the like, extending from the second part away from the second hole and the first hole for insertion into the explosive material of the linear shaped charge. The prongs may, for example, extend from a wall of the second component and may be circumferentially spaced around the second aperture. With the tip inserted into the explosive material of the linear shaped charge, the DWC can be held firmly in place for detonation to occur. In other examples, the second component may include one or more tabs 44, each of which may be considered a tab or other element extending outwardly from the second component. At least one tab may be hingeable 45 with respect to the hollow element of the second component. Further, at least one tab may be foldable along one or more creases or thinned portions 46 of the tab. Such hinging and folding capabilities increase the options for attaching the DWC to the linear shaped charge. For example, the tabs may be hinged up or down to accommodate the DWC in a narrow space, and folding the tabs may shorten their length or enable their attachment to a surface in different orientations. A tab may be attached to the linear shaped charge using an adhesive, such as tape, to hold the DWC in place for detonation. Furthermore, either the prongs or the tabs may be removable, e.g. by breaking or cutting them off the second part using a suitable tool, in case they are not compatible for a given situation of attaching the DWC to the linear shaped charge. For example, when the DWC is used with a third member described later, the tips may be removed so they do not interfere with the detonation wavefront output from the second aperture.

Figures 5, 6 and 7 schematically show a DWC 2 in different configurations attached to a linear shaped charge 48. Further details of such a linear shaped charge are explained later, but in fig. 5, 6 and 7 there is shown in cross-section a housing 50 (such as foam in fig. 5 and 6 and plastic casing in fig. 7), explosive material 52, a liner 54 and an abutment space 56 which may be at least partially filled with foam, and the target to which the linear shaped charge is attached. In fig. 5 and 6, the DWC is attached to the explosive material of the linear shaped charge through a cut in the housing and thus the second hole is in contact with the explosive material using the above-mentioned tip which is inserted into the explosive material 52. In fig. 7, the second member of the DWC is engaged with a third member 56 which will be described later. In the example of fig. 7, the third part is formed as part of the housing 50 of the linear shaped charge, but in other examples the third part may be part of a DWC and may be attached to the linear shaped charge, for example by tabs or prongs such as those described above.

In fig. 5, the DWC is in the first configuration described above. In fig. 6, the DWC is in the second configuration described above. In fig. 7, the DWC is in a third configuration, which is explained further below. In each of fig. 5 to 7, the initiator 14 is inserted into the first member and held by the initiator holder. Upon detonation, the detonator emits a detonation wavefront. In an example, the narrowest portion (such as the apex or tip) of the volume through which the detonation wavefront propagates (which may be conical or frustoconical) is at the end of the detonator that is inserted into the first component. In the first configuration, the first aperture is, for example, substantially in the same plane as the second aperture and is thus in contact with the explosive material of the linear shaped charge, the emitted detonation wavefront being transmitted directly into the explosive material. Accordingly, the first distance D1 may be near or approximately zero and is not shown in fig. 5. The propagation of the wavefront is schematically illustrated in fig. 5 by wavefront lines 60. In the first configuration, where the output of the detonator is closer to the explosive material of the linear shaped charge than in the second configuration, the detonation wavefronts may correspond to those output by the detonator without modification, and may have a smaller radius than the detonation wavefronts input to the explosive material in the second or third configuration.

In contrast, in the second configuration, the second distance D2 illustrates the spacing of the first and second apertures. In the event that the second distance D2 is greater than the first distance D1 and the second width of the second aperture, the detonation wavefront output from the detonator can be modified by the second component. The profile of the cross section of the volume through which the detonation wavefront propagates within the DWC is shown by dashed line 62; the shape of the volume is for example conical or frustoconical. At least the second diameter and the second distance determine the size of the conical or frusto-conical shape. With this modification of the detonation wavefront by the DWC in the second configuration, the detonation wavefront in the explosive material input to the linear shaped charge has a larger radius than in the first configuration. Thus, as can be seen in fig. 6, the detonation wavefront interacts with the liner 54 in a less curved, flatter and flatter shape as compared to the first configuration of the DWC. As a result, the amount of energy per unit area of liner and, in turn, received by the target from detonation of the explosive material may be less than in the first configuration.

As a result, in the first configuration, the energy from detonation of the explosive material may be more concentrated in the region directly between the DWC and the target, rather than in a region peripheral to that region. Such firing behavior of a linear shaped charge may be desirable in applications that require energy from the detonation of an explosive material to be transferred at a rapid rate to a liner and then to a target but over a smaller area for a more abrupt cutting action to the target. The form of the wavefront with the smaller radius may cause a portion of the wavefront to propagate laterally (perpendicular to the longitudinal axis of the linear shaped charge) and thus may be emitted 64 from the end of the explosive material. This effect may be referred to as run-on and may be used to initiate explosive material of a separate charge placed in contact with the initially detonated linear shaped charge, or to cut a portion of the target extending beyond the end of the linear shaped charge.

In contrast, in the second configuration, the energy from the detonation of the explosive material is more spread along the liner and then along the target, so that the energy from the detonation of the explosive material can be transferred at a slower rate and over a larger area than in the first configuration. This may be considered to be a more gradual or continuous delivery of energy to the target than in the first configuration, which may be more suitable for certain target materials than other configurations, where a slower rate of energy transfer to the target is required over a longer period of time. This may be contrasted with the higher energy transfer over a shorter period of time and a smaller area in the first configuration. For the second configuration, it may be desirable to detonate the linear shaped charge at more than one point along the length of the linear shaped charge, for example using multiple DWCs in the second configuration. This may be referred to as an array arrangement, and each shot may be initiated by a separate detonator, or may be initiated by one detonator connected to other DWCs with a detonating cord as explained later. A similar method may be used for the third configuration described below. As mentioned above, the wavefront lines 60 are shown schematically, and therefore their curvature and the spacing between the wavefront lines should not be considered limiting. Indeed, it is noted that the particular explosive material used may affect the velocity of the wavefront propagating through the explosive material, and in turn, for example, the spacing (e.g., wavelength) between the lines of the wavefront, the curvature of the wavefront in the plane of fig. 5-7, and/or the rate of change of curvature with the propagation of the wavefront. Thus, in addition to selecting a desired configuration of the DWC for a particular firing behavior, a particular explosive material may be selected to further tailor the firing behavior of the linear shaped charge. The rationale for selecting a particular explosive material is similarly applicable to any explosive material provided in the space of a DWC; for example, the explosive material of one or more projectiles (described below) may be selected to help tune the wave front shape and propagation behavior of the wave front from the initiator to the linear shaped charge.

The first and second configurations have been described as being designed to have predetermined first and second distances D1 and D2 and first and second widths W1 and W2 in the DWC for controlling the detonation wavefront between the two desired forms. In such examples, the second width may be at least three times the first width, and the thickness of the portion of the wall of the first component may be set accordingly.

It will be appreciated that the first and second distances and the first and second widths or diameters may be selected to determine the design of a particular DWC embodiment to provide a linear shaped charge having two desired ignition behaviors. For example, these configurations may be arranged to be used with the same type of linear shaped charge, or may be arranged such that the DWC enables a standard type of detonator to be used over a much different range of linear shaped charge types.

Further, the DWC may be arranged in more than the first configuration and the second configuration. For example, the user may obtain at least one intermediate configuration by moving the first and second components to positions relative to each other between the positions of the first and second configurations. Thus, the user may be provided with a so-called dial-in function so that they may dial in, or otherwise, adjust the DWC to output a desired detonation wavefront from multiple options between the first configuration and the second configuration.

Further, in further examples, the DWC may be engaged with or may include at least one additional component. Such a component may for example be the third component described previously. The third member may be part of a housing of the linear shaped charge, the second member being engaged therewith; or in other examples, may be separate parts of the DWC, which may be joined if desired; or alternatively a movable part of the DWC, which can be moved relative to the first and second parts, for example with a telescopic action as described above. With the third component engaged with the second component, the DWC is in a third configuration, such as shown in fig. 8. Fig. 9a to 9d show the third part 66 in perspective, side, bottom and top views, respectively.

The third component comprises, for example, a hollow element, such as a tube or tubular structure, the cross-section of which (taken perpendicular to the longitudinal axis LA) may be circular, and thus cylindrical in shape. But other cross-sectional shapes corresponding to the cross-sectional shape of the second component are conceivable. The third component is configured to receive the second component at least partially within a hollow or cavity within the third component. Thus, the cross-sectional diameter of the inner surface of the third piece is larger than the cross-sectional diameter of the outer surface of the portion of the second component intended to be received within the third component. Thus, the second component may be at least partially inserted within the third component and engaged at a predetermined position relative to the second component to position the third aperture at a third distance from the first aperture.

In the depicted example, the third component 66 has a hole 68 or opening at one end that is shaped and sized to receive the second component, and the hole may be circular. The third component has an aperture (referred to herein as the third aperture 70) at the other end through which the detonation wavefront is output. The third hole has a third width W3, for example a third diameter in the case where the hole is circular. As shown in fig. 7, with the third component engaged with the second component, a third distance D3 exists between the first and third apertures. Further, the third width is greater than the first width and the second width. For example, the third width may be at least five times the first width. As indicated by dashed line 62 in fig. 7, the conical or frustoconical shape of the volume through which the detonation wavefront propagates is determined by the third distance and a combination of the first, second, and third widths. By appropriate selection of the third distance and the first, second and third widths in the design of a particular embodiment of a DWC, a desired detonation wavefront form of the third configuration, along with desired forms of the first and second configurations, may be determined. Thus, the first, second and third bores each correspond to respective and different cross-sectional profiles in different planes (perpendicular to the longitudinal axis LA) of the predetermined conical or frustoconical shape.

In the third configuration, the detonation wavefront output by the DWC may have an even larger radius than the second configuration, which delivers energy over a larger area than in the second configuration, and thus gives the target a more gradual or continuous delivery of energy than the second configuration. This can be seen by the wavefront 60 shown in fig. 7.

The third component may be suitably engaged with the second component. For example, the outer surface of the second component may have at least one protrusion or recess for engaging with a corresponding recess or protrusion, respectively, of the inner surface of the third component. Such protrusions and/or depressions may be located at predetermined points relative to the longitudinal axis LA to set a third distance when the second and third components are engaged for a third configuration. Fig. 9a to 9d show such a protrusion, in this example a pin 72 on the inner surface of the third part, and a recess, in this example a slot 74 or groove, into which the pin can be inserted by twisting one of the second and third parts and then slid in the circumferential direction to keep the second and third parts from separating. Such a mating mechanism may be referred to as a bayonet fitting.

It is envisaged that a fourth or further component similar to the third component but having a larger aperture through which the detonation wavefront is output may be provided, thereby giving the user greater flexibility to select different ignition behaviour of the linear shaped charge. Furthermore, the size and proportions of the first, second, third and/or possibly further components may be selected based on the size and/or explosive load of a given or common linear shaped charge to set the DWC to a configuration that gives a predetermined firing behavior of a given linear shaped charge, or a series of firing behaviors of different types of linear shaped charges.

In the above example, where the detonator is held by the detonator retainer, there may be a space between the detonator and the second hole. This may also be the case in the second configuration as well as in the third configuration, wherein there is also a space between the second bore and the third bore. Any such space may be filled with a projectile or volume of explosive material as an intermediate stage in the detonation chain of explosive material from the detonator to the linear shaped charge. Such a projectile 70 is shown in various figures with diagonal shading, such as in fig. 10. Such a projectile may be referred to by the skilled person as a booster. In some examples, such projectiles or other explosive materials may be conformable or bendable by a user to fit into the space, while in other examples such projectiles or other explosive materials may be solid, rigid, or have a pre-formed shape for insertion into the space.

Figure 10 shows how a detonating cord or shock tube can be used with a DWC. The example DWC gives the user the flexibility to detonate one or more linear shaped charges, which may be of different types, with different firing behaviors and possibly using a detonating cord or so-called shock tube to assist the firing of the one or more linear shaped charges.

Detonating cords are well known to the skilled person and are for example lengths of plastic tube filled with explosive material. The detonating cord can be cut to a desired length for use and upon initiation, energy can be emitted radially in a direction perpendicular to the longitudinal axis of the cord. Examples of detonating cords are the so-called L5A detonating cord (available from Chemring Energetics UK) or the so-called L5 detonating cord(available from Dyno Nobel inc.,2795East Cottonwood, park way, Suite 500, Salt Lake City, UT 84121, u.s.a.).

Shock tubes are also well known to the skilled person and are for example lengths of plastic tube, the inner surface of which is coated with an explosive material. In contrast to detonating cords, it is generally not possible to cut the length of the shock tube as desired because the effectiveness of the shock wave transmitted along the tube upon initiation will be compromised. In addition, the shock tube does not emit energy radially as the shock wave passes along the tube.

In an example, the wall of the second part of the DWC may for example comprise a plurality of wall holes 76 or openings. Such openings may be shaped and sized to accommodate one cross-section of the detonating cord, or more if stacked in a direction parallel to the longitudinal axis LA. Thus, each wall hole may be wider at the end further from the second hole for insertion of the detonating cord and then may narrow in a direction towards the second hole so that the detonating cord may slide towards the second hole and be retained by the narrower portion of the wall hole.

Figure 10 shows a first length of detonating cord 78 passing through a pair of wall apertures opposite one another. The detonating cord is contacted within the second member with the projectile 70 of explosive material and may also be contacted with a detonator held by the detonator retainer of the first member, wherein the first member moves into the second member sufficiently to press the first aperture against the detonator, which in turn presses the detonating cord against the projectile, which in turn presses the projectile against the explosive material of the linear shaped charge to effectively transfer energy to the linear shaped charge. The detonating cord may extend to the second DWC to detonate the same linear shaped charge at different locations along its length, or to detonate different linear shaped charges as part of an array of linear shaped charges.

In examples such as shown in fig. 11 and 12, the plurality of wall apertures includes a first pair of wall apertures that are opposite each other and a second pair of opposite wall apertures that are opposite each other. In this manner, the first portion of the detonating cord 78 can be initially passed through the first pair of wall apertures, as described above. A second portion of the same detonating cord or a different detonating cord 80 can pass through a second pair of wall holes, which can lie in a longitudinal plane perpendicular to the first pair of wall holes. As mentioned above, more than two sections or detonating cords can be stacked and pressed together in this manner by moving the first component sufficiently into the second component. Such stacking using more than one detonating cord may be used to detonate more than two additional components of the same linear shaped charge, or two additional linear shaped charges, using one detonator. Alternatively, stacking two portions of the same detonating cord can reduce the chance of detonation failure, as the detonator can act on two detonating cord portions instead of one. In this manner, the DWC may be used as a clamp or other fastener to clamp or secure two portions of the same or different detonating cords together.

A shock tube may be used in place of the detonator, whether or not the detonating cord is inserted through a wall hole. Accordingly, the detonator retainer can be configured to retain the shock tube rather than the detonator by passing the shock tube through the first member such that the end thereof contacts the detonating cord or pellet 70. Alternatively, in the above example, a shock tube may be used instead of the detonating cord. In other examples, a combination of detonating cord and shock tube may be used; for example, referring to fig. 12, the feature 78 may be part of the shock tube and the feature 80 may be part of the detonating cord such that the detonating cord in turn initiates detonation of the shock tube. Portions of the shock tube and the detonating cord can be inserted into different pairs of opposing bores of the detonation wavefront controller such that the shock tube portion is not parallel to the detonating cord portion; in other examples, to increase the contact area between the impact tube portion and the detonator cord portion, these portions can be inserted into the same pair of opposing holes such that the detonator cord portion and the impact tube portion are parallel or aligned with each other.

Figures 13 and 14 show examples of two different types of linear shaped charges in cross-section, taken perpendicular to the longitudinal axis of the charge. The previously described features are labeled with the same reference numerals. The linear shaped charge comprises explosive material 52, a liner 54, and in some examples a surface or face 81 for application to a target, wherein the liner is arranged to protrude towards the face when the explosive material is detonated. For example, as the skilled person will readily appreciate, prior to detonation, the liner may be a longitudinal element having a V-shaped cross-section and formed, for example, from copper or a material comprising copper or another suitable metal. The apex of the V-shape is located further away from the target than the sides of the V-shape. The linear shaped charge may comprise a space 56 between the liner and the face through which the liner is arranged to protrude after detonation of the explosive material (on the side of the liner furthest from the target). At least a portion of the space may be filled with a filler material and/or surrounded by a shell 82 formed of foam or plastic. The linear shaped charge may further comprise a housing 50 surrounding at least a portion of the explosive material. The shell and/or the filler material may comprise plastic or foam, such as Low Density Polyethylene (LDPE) foam. The housing and the filler material may be integrally formed. The linear shaped charge may be flexible along the longitudinal axis. This allows the target to be cut in a curved shape when the linear shaped charge is detonated. In an example, flexible generally means that the linear shaped charge may be bent, twisted or otherwise deformed, e.g. by hand, e.g. by a person without any tools, e.g. along or relative to the longitudinal axis of the linear shaped charge. The linear shaped charge may have elastic properties such that the linear shaped charge at least partially returns to a pre-deformed configuration. In other examples, the linear shaped charge may have plastic properties such that, for example, the linear shaped charge at least partially maintains a deformed configuration after deformation. In some examples, the linear shaped charge may be similar to the linear shaped charges described above, but it is substantially inflexible and therefore not deformable by hand, for example, without any tools. Such examples may include a linear shaped charge with a rigid copper or other metal liner. In some examples, such as shown in fig. 14, the housing 50 is formed to provide the third component 66 described above to engage with the second component of the DWC. Thus, the linear shaped charge may be configured to engage with the second part of the examples described herein. The linear shaped charge comprises one or more such third parts 66 spaced apart along the longitudinal axis of the linear shaped charge, each third part being integrally formed as part of the linear shaped charge, for example in the housing 50. It is envisaged that in alternative examples the linear shaped charge may comprise one or more openings or ports, for example in the housing and suitably spaced from each other, each for receiving a DWC therein for insertion into explosive material, as described above.

The examples of DWCs described herein provide the user with various options for controlling and selecting different firing behavior of the linear shaped charge. This gives the user more options when it is desired to successfully achieve a given cutting task with a linear shaped charge. The DWC may be made of nylon plastic or so-calledTSS/4 (available from EMS-Chemie AG, Via Innovativa 1,7013Domat/Ems, Switzerland).

The above examples are to be understood as illustrative examples. Further examples may be envisaged.

In the above examples, the various holes are described as circular, such as a first hole, a second hole, and a third hole. The circular shape of any such aperture may be taken in a plane perpendicular to the longitudinal axis LA of the DWC and has a center of the circular shape coincident with the longitudinal axis LA such that the circular shape has a constant radius about the longitudinal axis LA. In this manner, the effect of any such aperture shape on the detonation wavefront may be applied uniformly, e.g., radially, about the longitudinal axis LA. In further examples, any such hole may not be perfectly circular, but may be substantially circular, for example within acceptable manufacturing tolerances (and thus taking into account any imperfections or minor irregularities in shape due to imperfect manufacturing processes). In other examples, one or more of the first, second, or third apertures may be, for example, annular polygonal in shape. A circular polygon may be considered to be a circular polygon, all of the vertices of which lie on a common circle. In other words, a single circle can be drawn on which all the vertices of the annular polygon lie. Such a single circle may be considered a circumscribed circle. Various shapes of such apertures are contemplated, each shape being an annular polygon, including regular and irregular polygons; specific examples include triangular, square, hexagonal, octagonal, decagonal, or dodecagonal. In alternative examples, any such aperture may be considered to be approximately circular in shape, such as elliptical. Such an annular polygon may be substantially an annular polygon or such an ellipse may be substantially an ellipse, taking into account any acceptable manufacturing tolerances.

Thus, in examples, the aperture (which may correspond to a respective edge of the inner surface of the wall of the first, second, and/or third component) or the inner surface of the wall of the first, second, or third component may be free of protrusions or other inwardly extending structures that may interfere with, and in some examples may detract from, the generally radially uniform nature of the detonation wavefront as it propagates through the DWC.

In the above example, the DWC is inserted into the longitudinal surface of the explosive material of the linear shaped charge. It is envisaged that in further examples the DWC may alternatively be inserted into the end of the explosive material of the linear shaped charge. In this manner, when detonated, the detonation wavefront may propagate along the length of the linear shaped charge parallel to the longitudinal axis. Such detonation may maximize so-called continuity, in which the cutting jet extends from opposite ends of the linear shaped charge. This gives the user more options to select the desired firing behavior of the linear shaped charge.

In the above examples, any of the first, second, third and possibly further such components of the DWC may be provided separately from one another, for example as part of a kit in which a user may select the appropriate components to assemble a desired DWC. Alternatively, any of such components may have been engaged with one another such that the DWC is ready to be set to the desired first, second, third, or possibly intermediate configuration for use.

It is to be understood that any feature described in relation to any one example may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the examples, or any combination of any other of the examples. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the accompanying claims.