Abstract:
The present invention relates to a non-lethal projectile. The projectile ( 1 ) comprises a longitudinal body ( 5 ) having internally a longitudinal striker ( 55 ) suitable for perforating a container ( 47 ) of fluid under pressure in controlled manner, in particular by impact of the projectile ( 1 ) on a target. The striker ( 55 ) has an internal passage ( 59 ) opening to the outside of the body ( 5 ) via channels ( 60 ) made through a rigid wall ( 35 ) secured to the body ( 5 ) such that the outlet offered to the fluid under pressure remains disengaged even if the impact is accompanied by the deformation of the container ( 47 ). The fluid contained in the container ( 47 ) can thus escape and spread over the target even in such a case.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a non-lethal projectile adapted to be projected, in particular fired from a tube in a predetermined longitudinal direction, and to disperse a pressurized fluid in a controlled manner, in particular by impacting on a target in said direction. 
     BACKGROUND OF THE INVENTION 
     In the present context “tube” means either a weapon barrel housing the projectile directly until it is fired or a tubular case surrounding the projectile at least locally within the weapon barrel and remaining in the barrel when The projectile is fired. 
     European Patent Application No. 96400608.4 filed Mar. 22, 1996 by the Applicant describes an embodiment of a projectile of the above kind for dispersing a pressurized incapacitating or marking fluid in which the fluid dispersing means comprise a plurality of transverse orifices in a part of the body housing the container in the immediate proximity of the transverse wall carrying the striker. This prior art projectile is designed to be fired in a particular longitudinal direction from a weapon barrel and to release the pressurized fluid from the container as a result of inertial striking on impact on a target in that direction. 
     The above solution is not totally satisfactory in that the impact energy can be sufficient to cause not only striking (i.e. perforation) of the container by the striker, but also crushing of the container against the transverse wall carrying the striker, with the effect of crimping the container inside the body and/or to the striker in the immediate proximity of the aforementioned transverse wall, i.e. in the area in which the orifices are located. 
     This causes at least partial blocking of the orifices, making the projectile less effective. It is important for the fluid not only to exit the projectile but also to exit it in an extremely short time period, i.e. before the projectile falls to the ground after striking its target. 
     Also known, from FIG. 7 of British patent No. 1 354 307 is a projectile comprising, inside a body, a container which, on impact of the projectile on a target in a determined longitudinal direction, breaks against a striker so that its content escapes via lateral vents formed through the wall of the projectile body around the container, i.e. on the same side as the latter of a wall carrying the striker, as in the case of the projectile described in the above-mentioned European patent application. 
     Nevertheless, the container described in British patent No. 1 354 307 is not suitable for being perforated, but breaks into numerous pieces when it hits the striker, thereby making it necessary to provide firstly a cushion behind the container, in particular to protect it while the projectile is being fired, and secondly grids inside the vents to prevent pieces of the container from escaping together with the content thereof, since that would run the risk of injuring people in the vicinity. 
     In contrast, the present invention relates to projectiles in which the container is suitable for being perforated and opens on being perforated by means of the striker, as taught in the above-mentioned European patent application. 
     Also known, from U.S. Pat. No. 1,671,364, is a projectile having a tube that dips permanently into a volume containing a fluid to be expelled and communicating with channels formed in a rigid wall of the projectile. 
     The volume described in that document is no more a container suitable for being perforated than is the container described in the above-mentioned British patent, and the volume does not contain a fluid under pressure which is released by such a container being perforated. Release is performed by the effect of the volume telescoping and disengaging stoppers that initially closed a T-shaped end of the tube remote from the rigid wall in which the outlet channels are provided. 
     Consequently, neither British patent No. 1 354 307 nor U.S. Pat. No. 1,671,364 relates to a projectile implementing a container suitable for being perforated by the effect of a striker, i.e. of the type described in the above-mentioned European patent application. In particular, neither of those documents teaches means for remedying the above-mentioned drawback of the projectile described in said European patent application. 
     SUMMARY OF THE INVENTION 
     The present invention aims to remedy that drawback of the projectiles described in European Patent Application No. 9640068.4, and to this end it proposes a projectile of the type indicated in the preamble characterized in that the fluid dispersing means include a blind longitudinal passage through the striker open at the end towards the container and closed inside said wall, and a plurality of transverse passages in said wall radiating from said passage and discharging externally of the body. 
     The skilled person will readily see that under these conditions any crushing of the container against the transverse wall carrying the striker has no effect on the exit of the pressurized fluid and that it is therefore certain that the projectile in accordance with the invention will release the fluid that it contains in a very short time period after impact on its target if striking is caused by inertia on impact. 
     An embodiment of the fluid dispersing means of the above kind naturally accommodates any mode of striking the container, i.e. the use of any phenomenon able to bring about longitudinal movement towards each other of the container and the striker under conditions such as to cause the striker to perforate the container, in particular on impact on a target and given that the impact energy is intentionally limited to assure the non-lethal character of the projectile. 
     Striking can involve longitudinal movement of the striker relative to the transverse wall that carries it but it is preferable for the striker to be attached to that wall. Striking can then result from longitudinal crushing of the body, in which case the means for enabling or causing longitudinal movement towards each other of the container and the striker and perforation of the container by the striker include a longitudinally compressible area of the body between the container and the transverse wall in the longitudinal direction or such crushing is complemented or replaced by inertial sliding of the container inside the body towards the striker, in which case the means for enabling or causing longitudinal movement towards each other of the container and the striker and perforation of the container by the striker include mounting the container so as to slide longitudinally relative to the body, the striker and the wall being in front of the container. 
     The above two designs of the means for enabling or causing longitudinal movement towards each other of the container and the striker and perforation of the container by the striker can be combined and different means can be chosen, for example pyrotechnic means initiated by the impact or by firing the projectile, with a time-delay in the latter case, these examples being in no way limiting on the invention. Striking by longitudinal crushing of the body is associated with striking caused by the inertia of the body itself upon impact on a target in a particular longitudinal direction while striking by sliding of the container towards the striker is compatible with any mode of striking, in particular one relying on the inertia of the container on impact on a target in a particular longitudinal direction or on pyrotechnic or mechanical-pyrotechnic means that generally do not require an impact to supply the striking energy. 
     The skilled person will readily see that applications of the present invention are not limited to projectiles designed to be fired from a tube in a particular longitudinal direction and to release the pressurized fluid from the container on impact on a target in that direction and that projectiles can be made in accordance with the present invention that are designed to be projected by other means, in particular to be launched by hand in the manner of hand grenades. In such cases striking preferably relies on mounting the container to slide longitudinally relative to the body towards the striker but is advantageously achieved by means other than inertia, in particular by pyrotechnic means or mechanical-pyrotechnic means known in themselves and actuated intentionally by a user prior to launching to cause release of a gas causing the container to slide towards the striker and to be perforated by it, generally with a time-delay relative to such intentional actuation. The concepts of longitudinal and a particular longitudinal direction and derived concepts such as transverse, front and rear, nose and tail of the projectile, refer to the direction of movement of the container within the body towards the striker. 
     If striking relies on mounting the container to slide longitudinally relative to the body and in the case of a projectile designed to be fired from a weapon barrel the projectile in accordance with the invention advantageously includes locking means which immobilize the container relative to the body while the projectile is inside the barrel and release the container automatically so that it can slide longitudinally relative to the body when the projectile exits the barrel. 
     In one particularly simple but effective embodiment of such locking means the body is in the form of a wall of an elastically deformable material between the nose and the tail and has a smooth inside face to guide the container as it slides longitudinally in the body and a smooth outside face to guide the projectile as it slides longitudinally in the tube, the outside face having a localized protuberance adapted to be depressed to form a projection on the inside face when the projectile is engaged in the tube and to project from the outside face, eliminating the projection on the inside face, when the projectile has left the tube and the container has a localized transverse depression facing this protuberance when the container is juxtaposed to the striker. 
     The localized depression in the container can advantageously be in the form of a transverse annular groove and the protuberance on the wall of the body can then be in the form of a transverse bead joined to that wall without any discontinuity. The wall of the body of the projectile can incorporate at least one elastically flexible tongue having one end attached to the wall and offset relative to the protuberance and a free end carrying the protuberance and to which the protuberance is attached: there is preferably a plurality of tongues equi-angularly distributed around the wall of the body and the tongues are advantageously longitudinally oriented. 
     In all its embodiments the aforementioned protuberance not only prevents the container from sliding inside the tube, which could lead to accidental striking, but also contributes to retaining the projectile inside the tube in that it is urged elastically towards the exterior of the body and presses against the inside of the tube. In a particular instance where the protuberance is in the form of a transverse bead joined without discontinuity to the wall of the body, the protuberance further provides a seal between the projectile and the tube so that the projectile is fired by gas pressure developed inside the tube behind the projectile, for example the pressure of a gas such as compressed air introduced into the tube or the pressure of gases produced by combustion of a pyrotechnic charge. 
     In a manner that is widely known in the field of projectiles, when the projectile in accordance with the invention is designed to be fired from a weapon barrel in a particular longitudinal direction it advantageously has stabilizing fins attached to the tail end of the body and adapted to occupy a retracted position in which they are retained in an elastically stressed manner by the barrel when the projectile is engaged therein, their elasticity deploying them when the projectile has left the barrel. 
     The fins are advantageously made from an elastically deformable material and have one end attached to the body and a free end tending by virtue of its elasticity to spread transversely outwards relative to the end attached to the body, which is particularly simple, economic and reliable, and can advantageously be shaped to produce a whistling sound when the projectile is in flight which indicates firing and imminent impact. 
     The projectile in accordance with the invention can further include arrangements known in themselves such as a nose cone attached to its nose and made from an elastically compressible material, for example a material with a Shore A hardness in the range approximately 10 to approximately 30, preferably in the range 12 to 15, for example silicone. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features and advantages of a projectile in accordance with the invention emerge from the following description given by way of non-limiting example and from the accompanying drawings that form an integral part of the description. 
     FIG. 1 shows a projectile in accordance with the invention after it has left the tube but before it has impacted on a target, half in elevation and half in section on a half-plane defined by a longitudinal axis of the projectile. 
     FIG. 2 shows the detail II from FIG. 1 to a larger scale. 
     FIG. 3 shows the same detail when the projectile is still inside the tube. 
     FIG. 4 is a view similar to that of FIG. 1 showing the projectile after impact on its target, two different behaviors of the projectile on impact being shown in respective halves of this figure. 
     FIGS. 5 through 8 are views respectively corresponding to those of FIGS. 1 through 4 and show a different embodiment of the projectile, FIG. 6 showing a detail VI from FIG.  5 . 
     FIGS. 9 and 10 are sectional views analogous to those of FIGS. 1,  4 ,  5  and  8  of two preferred embodiments of a component combining the striker and the transverse wall carrying it. 
     FIGS. 11 and 12 are perspective view of these two preferred embodiments. 
     FIGS. 13 and 14 are views corresponding to those of FIGS. 4 and 8 but localized to the striker and the transverse wall carrying it and showing the co-operation of the container with the aforementioned two preferred embodiments after it is perforated following impact of the projectile on its target. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The respective embodiments of a projectile in accordance with the invention shown in FIGS. 1 through 4 and in FIGS. 5 through 8 are highly similar and their common parts are described first and are identified by the same reference numbers in all the figures. The description initially refers to all the figures. 
     The projectile  1  has a longitudinal axis  2  which, before the projectile is fired, lies concentric with a tube, for example a weapon barrel  3 , in which it is initially inserted and from which it emerges in a predetermined longitudinal direction  4  when fired. In the present context longitudinal and transverse are relative to the axis  2 , and front and rear are relative to the firing direction  4 . 
     The projectile  1  has a body  5  defined in the example shown by: 
     a longitudinal tubular wall  6  defined by circular cylindrical inside and outside faces  7  and  8  which are concentric with the axis  2  and smooth, with one exception to be described later, and by two plane circular transverse faces concentric with the axis  2 , namely a front face  9  and a rear face  10 , respectively connecting the faces  7  and  8  at the front and at the rear of the body  5 ; 
     a nose  11  defining a front end of the body  5  and fixed to the wall  6 , for example by nesting and gluing it in an area of its inside face  7  directly adjoining the front face  9 , the nose  11  being generally circular and concentric with the axis  2  apart from exceptions described below; and 
     a tail  12  defining a rear end of the body  5  and fixed to the wall  6 , for example by nesting and gluing it in an area of its inside face  7  directly adjoining its rear face  10 , the tail  12  having a generally circular tubular shape concentric with the axis  2 . 
     The tubular wall  6  is made from an elastically flexible material such as a plastics material from which the tail  12  can also be made. 
     The tail  12  has a wall  13  delimited by circular frustoconical outside and inside faces  14  and  15  which are concentric with the axis  2  and decrease in size towards the rear. Towards the front each of the faces  14  and  15  is joined to a respective circular cylindrical face concentric with the axis  2 , namely an outside face  16  having the same diameter as the outside face  8  of the wall  6  and an inside face  17  having a smaller diameter than the inside face  7  of the wall  6 . Towards the front, the outside face  16  is joined to a plane circular annular shoulder  18  concentric with the axis  2 , facing towards the front and abutting towards the front against the rear face  10  of the wall  6 . The shoulder  18  connects the outside face  16  to another outside face  19  of the tail  12 . The outside face  19  is a circular cylinder concentric with the axis  2  and substantially the same diameter as the inside face  7  of the wall  6  so as to espouse an area of the inside face  7  directly adjacent the rear face  10  of the wall  6 . The inside and outside faces  17  and  19  of the tail  12  therefore define, relative to the wall  13 , a tubular nesting rim  20  inside the wall  6 . Towards the front inside and outside faces  17  and  19  of the rim  20  are joined by a plane circular annular shoulder  81  concentric with the axis  2  and delimiting the rim  20  towards the front. The longitudinal distance between the shoulders  18  and  81  is much less than the longitudinal dimension of the wall  6  between its front and rear faces  9  and  10 . 
     Towards the rear, the outside and inside faces  14  and  15  of the wall  13  are joined to a respective circular cylindrical face concentric with the axis  2 , namely an outside face  22  and an inside face  21  joined at the rear by a plane circular annular shoulder  23  concentric with the axis  2  and facing towards the rear, delimiting a tubular end-piece  24 . 
     The tubular end-piece  24  is used to fix to the body  5  a tail fin assembly  25  adapted to spin the projectile  1  about the axis  2  after it is fired in order to stabilize its trajectory. 
     The tail fin assembly  25  is advantageously made by pressing and heat-forming a sheet of elastically flexible plastics material to define: 
     a flat fixing base  26  oriented transversely to and concentric with the axis  2  and having a central longitudinal hole  27  through it delimited by a circular cylindrical inside face  28  concentric with the axis  2  and substantially the same diameter as the inside face  21  of the end-piece  24  and an outside periphery  29  in the form of a regular polygon, to be more precise one with four sides in the example shown, inscribed within a circle having a diameter less than that of the outside face  8  of the wall  6 , referred to the axis  2 ; the central hole  27  and the inside face  21  of the end-piece  24 , which are appropriately screwthreaded, receive, from the rear, a bolt coaxial  30  for clamping the base  26  flat against the shoulder  23  of the end-piece  24  in order to attach the tail fin assembly  25  to the body  5 ; and 
     the same number of elastically flexible fins  31  as there are sides on the polygon defined by the periphery  29  of the base  26 , namely four fins  31  in the example shown, each fin having a front end  82  attached to the base  26  along one side of the polygon and a free end  83  at the rear which, by virtue of the elasticity of the material from which the tail fin assembly  25  is made, tends to spread transversely outwards relative to the front end  82 , in other words to a greater distance from the axis  2  than the front end, with the result that the tail fin assembly  25  has a rearwardly flared shape with a diameter greater than that of the outside face  8  of the wall  6  referred to the axis  2 . However, fins  31  can be folded towards that axis to a diameter corresponding to that of the outside face  8  of the wall  6 , which is the configuration of the tail fin assembly  25  when the projectile  1  is engaged in the weapon barrel  3 ; by virtue of their elasticity the fins  31  automatically return to the rearwardly flared position of the tail fin assembly  25  as soon as the projectile  1  has left the weapon barrel  3  when it is fired. 
     The fins  31  are helically shaped to spin the projectile  1  about the axis  2  during its flight between the weapon barrel  3  and its impact on the target in order to stabilize its trajectory. For example, each fin  31  has a first plane flat  32  the shape of a right-angle trapezium the side of which perpendicular to the bases coincides with a side of the periphery  29  of the base  26  to constitute the front end  82  of the fin  31  and the longer base of which extends to the free end  83  thereof, so that the first flat  32  has the oblique side of the trapezium towards the rear, defining a rectilinear fold  33  in the fin  31 , and a second plane flat  34  the shape of a right-angle triangle the hypotenuse of which coincides with the fold  33 , the longer side adjoining the right angle extending the shorter base of the right-angle trapezium defined by the first flat  32  at an angle to the shorter base so that the flat  34  is offset outwards relative to the flat  32  and the shorter side adjoining the right angle defining the free end  83  of the fin  31 . 
     The choice of the material for the tail fin assembly  25  and the conformation of the fins  31  will be advantageously made, in the field on the normal aptitude of the skilled person, such that the flight of the projectile  1  is accompanied by a whistling noise. 
     The nose  11  includes a flat rigid transverse wall  35 , for example a metal wall, delimited in the direction away from the axis  2  by an outside face  36  having a diameter substantially equal to that of the inside face  7  of the wall  6  inside which the wall  35  therefore nests with intimate mutual contact between the faces  36  and  7  in the immediate proximity of the front face  9  of the wall  6 . 
     Towards the front, the outside face  36  is joined to a plane circular annular shoulder  37  concentric with the axis  2 , the shoulder  37  facing towards the rear and bearing flat against the front face  9  of the wall  6  to limit entry of the wall  35  inside the wall  6 . In the direction away from the axis  2  the shoulder  37  is itself joined to a circular cylindrical outside face  38  concentric with the axis  2  and having the same diameter as the outside face  8  of the wall  6 , which the face  38  extends towards the front with no apparent discontinuity. In the direction away from the axis  2  the outside face  38  delimits a circular annular rim  39  concentric with the axis  2 , in one piece with the wall  35  and projecting towards the front. In the direction towards the axis  2  the rim  39  is delimited by a circular cylindrical inside face  40  concentric with the axis  2 ; towards the front it is delimited by a plane circular annular face  41  concentric with the axis  2  and which is joined to the outside face  38  by a rounded edge (no reference number) and to the inside face  40  by a circular annular flange  42  concentric with the axis  2  and projecting towards it relative to the inside face  40  in an area at the front end of that face. Towards the rear the inside face  40  of the rim  39  is joined to a flat front face  43  of the wall  35  which is transverse to the axis, to be more precise in the form of a disc perpendicular to and concentric with the axis  2 ; the face  43  is coplanar with the shoulder  37 , for example. 
     The face  43 , the face  40  and the flange  42  therefore define immediately in front of the wall  35  a cavity  44  to receive a nose cone  45  and to immobilize it, for example by crimping it by means of the flange  42  and gluing it; the nose cone is circular, concentric with the axis  2  and designed to withstand impact with the target and to this end is made from a material having the elasticity of rubber, for example silicone having a Shore A hardness in the range 10 to 30, preferably in the range 12 to 15, although this example is in no way limiting on the invention. To this end the nose cone  45  has a hemispherical shape projecting towards the front relative to the front face  41  of the rim  39 , the center of this hemisphere (no reference number) being located at the intersection of the axis  2  with a geometrical plane defined by the rim  41  and, projecting rearwardly into the cavity  44 , a cylindrical tenon prestressed in compression inside the flange  42  to achieve a crimping effect and glued flat against the front face  43  of the wall  35 , these examples of its fixing being in no way limiting on the invention. 
     Towards the rear, the wall  35  is delimited by a plane transverse face  46  parallel to the face  43  and in the shape of a circular annulus concentric with the axis  2 . In the direction away from the latter axis the face  46  is joined to the face  36 , the distance between the faces  43  and  46  also defining the longitudinal direction of the face  36  and consequently the depth to which the wall  35  is pressed inside the wall  6 , which distance is small in comparison to the longitudinal dimension of that wall between its front and rear faces  9  and  10  so that the longitudinal distance between the face  46  of the wall  35  and the shoulder  81  of the tail  12  essentially constitutes the free longitudinal dimension of the wall  6 . 
     A sealed container  47  of a pressurized fluid, in particular an incapacitating fluid or a marking fluid, to be dispersed by the projectile  1  after its impact on a target in the direction  4  is mounted to slide longitudinally inside the wall  6 , guided by the inside face  7  thereof over this longitudinal distance. 
     The shape of the container  47  is such that it can co-operate either with a slide attached to the container  47  and sliding longitudinally against the inside face  7  of the wall  6 , in a manner that is not shown but will be obvious to the skilled person, the inside face  7  of the wall o guiding this longitudinal relative sliding, or directly with the inside face  7  of the wall  6 , as in the example shown in which the container  47  is in the form of an aerosol cartridge having a circular tubular lateral wall  48  concentric with the axis  2  and essentially delimited in the direction away from that axis by a circular cylindrical outside face  49  concentric with that axis and having a diameter substantially identical to that of the inside face  7  of the wall  6  so that sliding contact is established between the faces  49  and  7  to guide fins relative longitudinal sliding. Towards the front the wall  48  is joined to (or advantageously made in one piece with) a flat end wall  50  perpendicular to the axis  4  and delimited towards the front by a plane face  51  in the form of a disc concentric with the axis  2  and in the direction away from the axis  2  joined to the face  49  by a rounded edge. Towards the rear the wall  48  is firmly and sealingly crimped to a filler valve mechanism  52  disposed on the axis  2  and facing towards the rear, the crimping producing to the rear of the outside face  49  a plane circular annular shoulder  53  concentric with the axis  2  and facing towards the rear. Nearer this shoulder  53  than the front face  51  the wall  48  is locally deformed towards the axis  2  so as to form inside the container  47  a rib limiting penetration of the valve mechanism  52 , which will be familiar to the skilled person, and this deformation creates in the outside face  49  of the wall  48  a depression in the form of a circular annular groove  54  concentric with the axis  2  and nearer the shoulder  53  than the front face  51 . 
     The longitudinal distance between the shoulder  53  and the front face  51  is less than the longitudinal distance between the shoulder  81  and the rear face  46  of the wall  35 , with the result that the container  47  can occupy the position shown in FIGS. 1 and 2 inside the body  5  and the projectile  1  in which the shoulder  53  bears rearwardly on the shoulder  81  of the tail  12 , the valve mechanism  52  being freely received in a coaxial arrangement inside the tail, and in which its front face  51  is spaced longitudinally from the rear face  46  of the wall  35 , which corresponds to the position that the container  47  occupies inside the body  5  of the projectile  1  before it is fired and in flight after it is fired and until impact occurs. 
     For such impact to perforate the end wall  50  of the container  47 , i.e. to release the fluid that it contains, the rear face  46  of the wall  35  has a striker  55  on its rear face  46  in the form of a hollow longitudinal needle projecting towards the rear along the axis  2 , the needle being beveled towards the rear and having a longitudinal dimension parallel to the face  46  substantially equal to the difference between the longitudinal distance between the shoulder  81  and the face  46  and the distance between the shoulder  53  and the face  51 ; as a result, in the position shown in FIGS. 1 and 2, i.e. in the position prior to impact, the striker  35  is brought into contact with the front face  51  of the container  47  with its shoulder  53  resting on the shoulder  81  of the tail  12 , as yet without any force. 
     The striker  55  is advantageously made in one piece with the wall  35  and is delimited in the direction away from the axis  2  by a circular cylindrical outside face  56  concentric with that axis and having a diameter significantly less than that of the inside face  7  of the wall  6 . The outside face  56  is joined towards the front to the rear face  46  of the wall  35  and towards the rear to a plane annular face  57  which is inclined to the axis  2 , for example at 45°, and faces downwards, which defines for the striker  55  a beveled free rear end and connects the outside face  56  to a circular cylindrical inside face  58  concentric with the axis  2  and delimiting inside the striker  55  a longitudinal passage  59  open towards the rear inside the beveled face  57  and extending towards the front as far as the inside of the wall  35 , where it is closed at the front. However, inside the wall  35  the passage  59  discharges into a plurality of passages  60 , of which there are eight in the example shown, and which radiate from it, radially relative to the axis  2 , as far as the outside face  36  of the wall  35  onto which they open. Each passage  60  is defined by a circular cylindrical inside face  61  concentric with a respective axis  62  perpendicular to the axis  2 , for example, the various axes  62  being equi-angularly distributed around that axis and the respective diameters of the inside faces  61  being equal to each other but less than the diameter of the inside face  58  of the striker  55 . The wall  6  has a hole  63  through it facing and coaxial with each of the passages  60  and delimited by a circular cylindrical inside face  64  concentric with the respective axis  62  and having a diameter identical to that of the inside face  61  of a passage  60  so that the passage  59 , the passages  60  and the holes  63  establish communication between the outside of the body  5  and a sealed cavity  65  defined by the walls  6  and  35  and the tail  12  and in which the container  47  is housed. Naturally other arrangements of the passages  60  in the wall  35  and other numbers of passages can be chosen without departing from the scope of the invention. 
     Accordingly, when the projectile  1  impacts on its target  66  in the direction  4  after leaving a weapon barrel, as shown in FIG. 4, because of its inertia the container  47  tends to continue to move forwards inside the wall  6 , which is immobilized in this direction by the target  66 , and bears with a high force towards the front on the striker  55  which perforates the end wall  50 . This frees the container  47  to slide towards the front relative to the wall  6  with the result that the container  47  moves forwards in the body  1  until the face  51  of its end wall  50  is pressed flat against the rear face  46  of the wall  35 , as shown in FIG.  4 . The pressurized fluid  68  initially enclosed in the container  57  escapes from it through the perforation  67  produced in this way in the end wall  50 , flowing towards the front through the longitudinal passage  59  in the striker  55  and then in the centrifugal direction relative to the axis  2  through each of the passages  60  and the holes  63  until it escapes transversely from the body  5  of the projectile  1  to spread over the target  66 . 
     This process, relying exclusively on sliding of the container  47  towards the front inside the body  5 , is shown in the right-hand half of FIG.  4 . 
     The left-hand half of the figure shows a different embodiment of the projectile in which the above effect is complemented or replaced by longitudinal crushing of the wall  6  on impact. 
     Longitudinal compression of the wall  6  can be encouraged at least in an area longitudinally between the container  47  and the transverse wall  35 , for example as shown in the left-hand half of FIG. 1, by making longitudinal cuts  69  part-way through the outside face  8  of the wall  6  and localized immediately to the rear of the rear face  46  of the wall  35 , the cuts having a longitudinal dimension preferably corresponding to approximately twice the longitudinal distance between the front face  51  of the container  47  and the rear face  46  of the wall  35  when, as shown in the right-hand half of FIG. 1, the front face  51  bears towards the front against the striker  55  with no force and without causing perforation. On impact, and as shown in the left-hand half of FIG. 4, the cuts  69  open and allow the formation in the wall  6  of folds  70  on the outside face  8  of the wall  6  projecting away from the axis  2 . This is accompanied by apparent shortening of the wall  6  between the shoulder  81  and rear face  46  of the wall  35 , forcing the end wall  50  of the container  47  against the striker  55 , which perforates it. The formation of the outward folds  70  prevents the presence of the container  47  inside the wall  6  impeding the apparent shortening of the wall  6  and impeding longitudinal sliding of the container  47  inside the wall  6  when the effects of apparent shortening of that wall and of sliding of the container  47  towards the front inside it combine to cause the striker  55  to perforate the end wall  50 . In all cases the arrangement of the passage  59  through the striker  55 , of the passages  60  inside the wall  35  and of the holes  63  facing the passages  60  prevents any impediment to the exit of the fluid initially contained in the container  47 . 
     Because of the high ductility generally evidenced by the materials, such as aluminum or aluminum-based alloys, from which the walls of the aerosol cartridges preferably used for the container  47  are made, imperfect tearing of the end wall  50  of the container  47  around the perforation  67  can occur, in the sense that the tearing produces in the end wall  50  a tongue that remains attached to the rest of the end wall and is pressed against the annular face  57  on which the passage  59  discharges longitudinally towards the rear, which blocks the passage  59  and consequently prevents the fluid reaching the passages  60  and the holes  63 . 
     This risk can be overcome or eliminated by shaping the striker  55  differently, for example as in a variant shown in FIGS. 9,  11 ,  13  or a variant shown in FIGS. 10,  12 ,  14 , it being understood that the other components of the projectile can be the same as in either of the embodiments described above. FIGS. 9 through 14 therefore show, identified by the same reference numbers as used in FIGS. 1 through 8, various components identical to components described with reference to those figures with the exception of localized differences that will now be described. 
     Referring at first to FIGS. 9,  11 ,  13  there is shown a variant of the striker  55  that differs from the embodiment thereof previously described only in that it has at least one transverse orifice through it, extending between its inside and outside faces  58  and  56  and therefore opening into the passage  59  and into the body  5  to the rear of the wall  35 , to be more precise at a longitudinal distance from the rear face  46  of that wall at least equal to and preferably greater than the thickness of the end wall  50 . 
     In the non-limiting example shown there are three such orifices  85 ,  86 ,  87  each of which is oriented along a respective axis perpendicular to the axis  2  and has a circular cylindrical periphery concentric with the respective axis and a diameter that is as large as possible within limits compatible with the mechanical strength of the striker  55  so as to offer to the fluid a cumulative flow cross-section that is as close as possible to that of the passage  59 . 
     To be more precise, in the example shown in FIGS. 9 and 13 in which the annular face  57  is oriented perpendicularly to the section plane, the orifice  85  is on an axis  88  in that plane and intersects the axis  2  perpendicularly where that axis intersects the geometrical plane (no reference number) of the face  57 ; the orifices  86  and  87  have a common axis  89  perpendicular to the plane of FIGS. 9 and 13 and intersecting the axis  2  perpendicularly between the intersection of the axis  88  with the axis  2  and the rear face  46  of the wall  35 ; they have the same diameter, which is less than that of the orifice. 
     Accordingly, even if striking the end wall  50  upon impact of the projectile  1  on its target produces a tongue  84  from the end wall  50  that is pressed against the face  57  and therefore blocks the passage  59  towards the rear, as shown in FIG. 13, the latter communicates with the interior of the container  47  via the orifices  85 ,  86 ,  87  which are to the rear of the end wall  50  and so enable the fluid in the container  47  to escape from it and exit the projectile  1  via the passage  50 , the passages  60  and the holes  63 . 
     Naturally, the scope of the invention would not be exceeded by choosing other arrangements to preserve communication between the inside of the container  47  after it is perforated and the passage  59 , even if a tongue  84  formed from the material of the end wall  50  should block it towards the rear. 
     Nor would the scope of the present invention be exceeded by conforming the striker  55  to prevent the formation of any such tongue  84  or at least blocking of the passage  59  thereby, and a variant of the striker  55  with this aim in view will now be described with reference to FIGS. 10,  12 ,  14 . The skilled person will readily realize that, although this variant is described independently of that shown in FIGS. 9,  11 ,  13 , the two variants could easily be combined. 
     In the variant shown in FIGS. 10,  12 ,  14  the striker  55  differs from that described with reference to FIGS. 1 through 8 only in that its free end at the rear is hollowed out by a step  90  offset towards the front relative to its annular face  57  in the area thereof nearest the wall  35  and opens longitudinally towards the rear in this area and transversely onto the inside and outside faces  58  and  56 . 
     To be more precise, in the example shown the annular face  57  has a localized interruption  91  in its area nearest the wall  35 , symmetrical about a plane perpendicular to the annular face  57  and including the axis  2 , namely the plane of FIG. 11, and the step  90  is delimited by two plane longitudinal faces  92 ,  93  symmetrical to each other about that plane and joined towards the rear to the annular face  57  on respective opposite sides of the interruption  91  therein and by a plane transverse face  94  facing towards the rear and connecting the two longitudinal faces  92 ,  93  together in front of the annular face  57 . However, the transverse face  94  is preferably at a longitudinal distance to the rear of the face  46  of the partition  35  greater than the thickness of the end wall  50  of the container  47 . 
     The two longitudinal faces  92 ,  93  are in a common plane (no reference number) parallel to the axis  2  and perpendicular to the plane of FIG. 11, for example. As shown here, the plane of the faces  92 ,  93  is preferably on the same side of the axis  2  as the area of the annular face  57  nearest the wall  35  so that the interruption  91  in the annular face  57 , and with it the step  90 , extends over less than half the periphery of the annular face  57 , for example over 120° referred to the axis  2 , this value being given purely by way of non-limiting example. 
     The skilled person will readily understand that other shapes can be adopted for the step  90  without departing from the scope of the invention. 
     When, as the projectile impacts on its target, the end wall  50  of the container  47  moves forwards, towards the wall  35 , it comes into contact with the striker  55  first by means of the area of the beveled face  57  at the greatest distance from the wall  35 , what perforates it and can lead to the progressive formation of a tongue  84  as the end wall  50  comes into contact with areas of the face  57  progressively closer to the wall  35 ; the tongue  84  tends to remain pressed against the face  57  in an oblique orientation relative to the axis  2 . When the end wall  50  reaches the interruption  91  in the face  57  it crosses the step  90 , the longitudinal faces  92 ,  93  and then the transverse face  94  of which straighten the tongue  84 , in such away as to tend to orient it parallel to the axis  2  before the end wall  50  abuts towards the front against the face  46  of the wall  35 , as shown in FIG. 14; when the container  47  stops against the face  46  of the wall  35  any tongue  84  that may have been formed from its end wall  50  is therefore oriented so that there is no risk of it blocking the mouth of the passage  59  of the striker  55  on the annular face  57 , i.e. it cannot in any way impede exit of the fluid initially contained in the container  47  via the passage  59 , the passages  60  and the holes  63 . 
     To prevent accidental perforation of the container before impact on a target  66 , and in particular during storage of the projectile, during loading of the weapon (not shown) and when the weapon is being handled, locking means are preferably provided to immobilize the container  47  relative to the body  5  while the projectile  1  is inside the weapon barrel  3  and to release the container  47  automatically so that it can slide longitudinally relative to the body  3  when the projectile  1  leaves the weapon barrel  3 . FIGS. 1 through 4 show a first embodiment of the locking means and FIGS. 5 through 7 show a second embodiment and it is to be understood that these embodiments are also compatible with the variants of the striker shown in FIGS. 8 through 14. 
     Refer firstly to FIGS. 1 through 4, which show the locking means in the form of a circular annular transverse bead  71  concentric with the axis  2 , projecting on the outside face  8  of the wall  6  of the body  5  in an area transversely facing the groove  54  and forming a depression in the outside face  49  of the wall  48  of the container  47  when the shoulder  53  bears towards the rear on the shoulder  81  of the tail  12  of the body  5 . 
     The bead  71  is continuous, joined with no discontinuity to the wall  6  and advantageously made in one piece with that wall. When, as shown in FIG. 3, the projectile  1  is inserted into the weapon barrel  3 , which has a circular cylindrical inside face  72  concentric with an axis coincident with the axis  2  and a diameter substantially identical to that of the outside face of the wall  6  in order to co-operate with the outside face  8  to guide the body  5  as it slides longitudinally in the weapon barrel  3  when fired, the bead  71  bears on the inside face  72  which compresses it towards the axis  2  which causes at least partly elastic deformation, and where necessary slightly plastic deformation, of the wall  6  in the direction towards the axis  2 . This forms on the inside face  7  of the wall  6  a circular annular bead  73  concentric with the axis  2  and projecting towards that axis relative to the inside face  7  of the wall  6 , i.e. entering the groove  54  to immobilize the container  57  relative to the wall  6  in the position with the shoulder  53  bearing on the shoulder  21 . 
     The bead  71 , which is stressed against the inside face  72  of the weapon barrel  3  because of the elasticity of the material of which the wall  6  is made, retains the projectile  1  because of friction between the inside face  72 , on the one hand, and a seal between the projectile  1  and the face  72 , on the other hand, in a manner that is particularly advantageous when, as is frequently the case, the projectile  1  is fired by accumulating pressurized gas between it and a bolt (not shown) closing the rear end of the barrel  3 , whether by introducing a pressurized gas or by generating a pressurized gas, for example by combustion of a suitable pyrotechnic substance. 
     When the projectile has left the weapon barrel  3 , as shown in FIGS. 1,  2 ,  4 , the elasticity of the wall  6  causes the bead  71 , which has been relieved of the pressure previously applied to it by the inside face  72 , to return to its original configuration, i.e. projecting on the outside face  8  of the wall  6 , which eliminates the bead  73  projecting on its inside face  7  and allows the container  47  to slide forwards inside the wall  6 . 
     Referring now to FIGS. 5 through 8, the bead  71  is dispensed with but appropriate cuts form elastically flexible tongues  74  in the wall  6 . There are eight such tongues, for example, oriented longitudinally and equip-angularly distributed around the axis  2 , although other arrangements and other numbers of tongues can be chosen without departing from the scope of the invention. 
     Each tongue  74 , which is therefore in one piece with the wall  6 , has one end  75 , here the front end, attached to the remainder of the wall  6  and a free end  76 , here the rear end, carrying and having fastened to it, for example in one piece with it, a protuberance  77  projecting away from the axis  2  on the outside face  8  of the wall  6  when, as shown in FIGS. 5,  6 ,  8 , the projectile  1  has left the weapon barrel  3 . Because of its elasticity the tongue  74  tends to retain a shape in which the corresponding part of the inside and outside faces  7  and  8  remains on the same respective geometrical cylinder as the remainder of the peripheral wall respectively inside or outside the wall  6 . 
     On the other hand, when the projectile  1  is inside the weapon barrel  3 , as shown in FIG. 7, the inside face  72  of the barrel bearing on the respective protuberance  77  eliminates the projection that the latter constitutes relative to the outside face  8  of the wall  6 , i.e. it causes each tongue  74  to flex towards the axis  2  at the position of the protuberance  77 , with the result that the free end  76  of each tongue  74  forms a projection towards the axis  2  on the inside face  7  of the wall  6 . Because the protuberances  77  have exactly the same location as the bead  71 , i.e. they coincide with the groove  54  in the wall  48  of the container  47  bearing through a shoulder  53  on the shoulder  81  of the tail  12  of the body  5  of the projectile  1 , the free ends  76  of the tongues  74  enter the groove  54  and constitute an abutment opposing movement of the container  47  towards the front inside the body  5 . 
     When the projectile  1  has left the weapon barrel  3  the force applied to its face  72  by the protuberances  77  is removed and the elasticity of the tongues  74  returns them to a position in which each protuberance  77  projects on the outside face  8 . The free ends  76  of the tongues  74  are therefore retracted away from the axis  2  relative to the inside face  7  of the wall  6 , freeing the container  47  to slide towards the front inside the body  5 . 
     Assuming that, instead of sliding directly inside the body  5 , the container  47  is mounted in a slide adapted to slide inside the body  5 , the bead  71  or the tongues  74  could co-operate in exactly the same way as described with reference to the groove  54  with a similar groove in the slide. A solution of the above kind is not shown but how to put it into effect will be evident to the skilled person. 
     Naturally, other modes of locking the container  47  or the slide carrying it inside the body  5  can be chosen without departing from the scope of the invention, in particular if the movement of the container  47  leading to its end wall  50  being perforated by the striker  55  is brought about not by inertial displacement of the container  47  or by apparent shortening of the wall  6 , as shown, but by other means such as pyrotechnic means with a time-fuse initiated when the projectile is fired. In this case, for example, the container  47  could be retained temporarily against sliding inside the body  5  by shear pins that break when the gas pressure generated by the aforementioned pyrotechnic means exceeds a predetermined threshold or when the combination of this effect and an inertia of the container  47  on impact exceeds the predetermined threshold at which the pins shear. How to construct this variant of the projectile  1 , and likewise of the other variants, will be evident to the skilled person and is within the scope of the invention. 
     Likewise, although applications of the invention to a projectile  1  adapted to be fired in a given longitudinal direction  4  from a weapon barrel  3  and to release the pressurized fluid  68  from the container  47  on impact on a target  66  in this direction have been described with reference to figs. 1 through 14, it will be obvious to the skilled person how to adapt these to the case of a projectile  1  adapted to be projected by some other means, in particular launched by hand, and/or how to release the pressurized fluid from the container in a manner other than in response to impact on a target in the particular longitudinal direction, in particular by striking of the container  47  as a consequence of its longitudinal sliding inside the body  5  of the projectile  1  towards the striker  55  and towards the transverse partition  35  carrying it by action of pyrotechnic or mechanical-pyrotechnic means known in themselves, in particular intentionally operated by a user prior to launching the projectile  1 .