Abstract:
An adapter device ( 10 ) is used in order to allow a projectile ( 12 ), such as missile, to be launched from a standard launching tube ( 14 ), without having to modify the latter. This device comprises an adapter tube ( 24 ) in which the projectile ( 12 ) is placed, a retaining ring ( 22 ) which is mounted on the end of the launching tube ( 14 ) and a hooking system ( 26 ) for securing the adapter tube ( 24 ) to the launching tube. The adapter tube ( 24 ) has a front portion ( 38 ) provided with grooves for guiding the folded fins of the projectile ( 12 ) and a rear portion provided with a bottom onto which is fixed a pulley ( 36 ) for returning an optical fiber ( 20 ) used for guiding the projectile ( 12 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority based on International Patent Application No. PCT/FR03/01978, entitled “Adapter Device For Projectile Launched From A Launching Tube” by Marc VALUER, which claims priority of French Application No. 02 08082, filed on Jun. 28, 2002, which was not published in English. 
   DESCRIPTION OF TECHNICAL DOMAIN 
   The invention concerns an adapter device for use in association with a projectile with deployable fins, such as a missile, to allow such a projectile to be fired from a launching tube of small diameter, such as a mortar or cannon tube. 
   The invention especially enables projectiles guided by optical fibres, or the like, to be fired from a launching-tube of standard dimensions, without having to modify the latter. 
   PRIOR ART 
   As evident especially from the document U.S. Pat. No. 4,907,763, it is known to fire a projectile guided by a cable or an optical fibre, from a mortar or cannon tube. 
   In this case, the projectile is guided in flight by deployable fins which lodge before firing in recesses provided for this purpose in the external envelope of said projectile. This arrangement implies mounting the fins on the envelope by means of complex articulated mechanisms. In addition, the presence of recesses in the external envelope of the projectile results in a reduction in the useful volume available inside the envelope of the projectile. 
   DESCRIPTION OF THE INVENTION 
   The object of the invention is an adapter device designed to allow a projectile such as a missile to be launched from a standard launching tube of small diameter, such as a mortar or cannon tube, without modification to said tube and without the necessity for housings or complex articulations for mounting the guide fins on the external envelope of the projectile. 
   According to the present invention, this result is obtained by means of an adapter device designed to be interposed between a projectile, fitted with deployable fins, for occupying a folded position, and a standard launching tube, said device being characterised in that it comprises a retaining ring for being mounted on an open end of the launching tube, an adapter tube for being placed around the projectile, such that in their folded position the fins are lodged in a first part of the adapter tube, and hooking means of the adapter tube on the retaining ring, in a position such that the first part of the adapter tube is located outside the launching tube and a second part of the adapter tube is received in the launching tube. 
   Utilisation of the adapter device according to the present invention allows projectile fitted with deployable fins to be fired from a standard launching tube whereof the internal diameter is slightly greater than the internal diameter of the body of the projectile, without it being necessary to modify the launching tube. In effect, the retaining ring mounted on the launching tube serves to anchor the hooking means of the adapter tube in which the projectile is placed. Mounting of the retaining ring on the launching tube can especially be completed by friction, by giving said ring the form of a split ring which is clamped by means of a bolt interposed between its ends. The folded fins of the projectile are received in the part front of the adapter tube, which acts as guidance for the projectile when launched. 
   According to a preferred embodiment of the invention, the first part of the adapter tube comprises longitudinal guide grooves terminating inside the adapter tube, so as to Be capable of receiving each of the fins of the projectile. 
   In this case, the first part of the tube advantageously comprises longitudinal external grooves and each of said longitudinal guide grooves is formed in the corresponding one of said longitudinal external grooves. 
   According to an advantageous realisation of the invention, the first part of the tube comprises an external ring adjacent to the second part of the adapter tube and capable of being supported against an open end of the launching tube. 
   Advantageously, the hooking means are then interposed between the retaining ring and the external ring of the adapter tube. 
   In this case, the hooking means can especially comprise dunking mechanisms. 
   According to an advantageous refinement, the device also comprises mobile transport elements including a front protective cap and a back protective cap, suitable for being placed respectively on the front and back ends of the projectile covered by the adapter tube, and a transport sling connecting said protective caps. 
   Preferably, an open end of the adapter tube, opposite the second part of the latter, is provided for placing behind auxiliary propulsion units of the projectile. 
   Advantageously, the projectile is a missile guided by an optical fibres. 
   In this case, the adapter tube generally comprises a closed end, opposite the first part of the latter, and a pulley for returning the optical fibre, mounted inside said closed end. 
   Finally, the launching tube is advantageously a mortar tube. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the invention will now be described, by way of illustrative and non-limiting example, with reference to the attached diagrams, in which: 
       FIG. 1  is a perspective view showing a projectile to be launched from a launching tube, an adapter device according to the present invention being interposed between the projectile and the tube; 
       FIG. 2  is a view in longitudinal section on a larger scale, showing especially the fins of the projectile taken up in grooves provided for this purpose in the adapter tube; and 
       FIG. 3  is a side elevation schematically showing the protective caps and the transport sling of the projectile place in its adapter tube. 
   

   DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
   In the overall description, the terms “front” and “back” are a reference respectively to the front and the back of the projectile placed in the launching tube by means of the adapter device. 
   As is illustrated schematically in  FIG. 1 , the invention concerns an adapter device  10  provided to be interposed between a projectile  12  such as a missile guided by an optical fibre and a standard launching tube  14  such as a mortar tube, so as to enable the projectile  12  to be launched without the necessity of modifying the launching tube. 
   More precisely, the projectile  12  comprises a cylindrical body, on which are articulated fins  16  ( FIG. 2 ) suitable for occupying a folded position illustrated in full lines and a deployed position (not shown). In the non-limiting embodiment shown in the figures, there are four fins  16 , evenly spaced on the circumference of the body of the projectile. Each of the fins  16  is plane and situated in a plane passing through the longitudinal axis of the body of the projectile. 
   Relative to its axis of articulation  18  on the body of the projectile, each fin  16  is suited to be folded to the front of the projectile  12 , such that its edge turned to the front when the fins are deployed abuts against the circumferential surface of the body of the projectile when the fins  16  are folded. 
   As is also evident from  FIG. 1 , the projectile  12  also comprises trimming propulsion units  18  (for example two) which join on the circumferential surface of the body of the projectile, at the front of the fins  16  when the latter are in the folded position. 
   As indicated above, the projectile  12  is guided by an optical fibre  20  utilised, in a known manner, to ensure the transmission of information between said projectile and a command post (not shown), after the projectile has been launched. 
   The optical fibre  20  is stored on a bobbin  21  placed in the back part of the body of the projectile  12 . It exits from said body via a central orifice formed on the back face of the latter. The optical fibre  20  then travels along the internal wall of the tube  14  or outside the body of the projectile  12 , according to a trajectory which will be specified hereinbelow, before emerging via the open end of the launching tube  14  to rejoin the command post. 
   The adapter device  10  according to the present invention essentially comprises a retaining ring  22 , provided to be fixed on the open end of the launching tube  14 , an adapter tube  24  designed to be placed around the body of the projectile  12  and hooking means  26  of the adapter tube  24  on the retaining ring  22 . 
   The retaining ring  22  is provided to be fixed by clamping on the launching tube  14 , in the immediate vicinity of its open end, without having to modify or machine said tube. Thus, the retaining ring  22  can especially be a split ring whereof the ends can be joined to one another by a rapid clamping device such as a bolt  28 . The effect of the clamping of the bolt  28  is to secure the retaining ring  22  of the end of the launching tube  14  by friction. On its external surface the retaining ring  22  carries a part of the hooking means  26  for immobilising the adapter tube  24  relative to said ring when a ensemble of projectile  12  and adapter tube  24  is placed on the launching tube  14 . In the embodiment show by way of example in the figures, said part of the hooking means  26  comprises two dunking mechanisms  30  mounted in emplacements diametrically opposite on the surface external of the retaining ring  22 . 
   As shown in  FIG. 1 , the adapter tube  24  is a tube having a length slightly less than that of the projectile  12  and whereof the internal diameter is uniform and slightly greater than the external diameter of the body of the projectile. The end front of the adapter tube  24  is open while the back end of said tube is closed by a base  32 . 
   Therefore, the adapter tube  24  can be placed around the body of the projectile  12 , such that the front end of the projectile  12  projects over a certain length over the open front end of the adapter tube  24 . The back end of the projectile  12  is then situated inside the adapter tube  24 , at a certain distance from the base  32  of said tube. The latter distance is determined by an external ring  34 , an integral part of the adapter tube  24 , coming to rest against the open front end of the launching tube  14 . 
   As shown in  FIG. 1 , this arrangement enables a pulley  36  for returning the optical fibre  20  to be mounted on the inner face of the base  32  of the adapter tube  24 . On leaving the end back of the projectile  12 , the optical fibre  20  travels on the return pulley  36  and returns to the open front end of the launching tube  14 , between the adapter tube  24  and the projectile  12 , to then be directed to the command post (not shown). 
   More precisely, the part of the optical fibre  20  which travels between the adapter tube  24  and the projectile  12  passes in a sleeve (not shown) provided for this purpose inside the adapter tube. This sleeve ensures mechanical and thermal protection of the optical fibre  20  during launch of the projectile  12 . 
   The external ring  34  is fitted on one hand with hooking means  26  of the adapter tube  24  on the launching tube  12 . In the embodiment shown, this other part of the hooking means  26  comprises two hooks  48  located in emplacements diametrically opposite on the surface external of said external ring  34 . The dunking mechanisms  30  mounted on the retaining ring  22  are arranged so as to be able to engage in the hooks  48  when the adapter tube  24  is placed in the launching tube  14 . The adapter tube  24  is then immobilised relative to the launching tube  14 . 
   The external ring  34  is situated substantially in the centre of the adapter tube  24  and separates the latter in a first part  38 , located in front of said external ring and a second part  40  located in back of said external ring. 
   The first part  38  of the adapter tube  24  comprises longitudinal guide grooves  42  ( FIG. 2 ) whereof each is provided to receive one of the fins  16  of the projectile  12 . More precisely, each of the longitudinal guide grooves  42  is formed in a longitudinal external groove  44  of the adapter tube  24  and is attached inside said tube over its entire length. In addition, the number and the distribution of the grooves  44  around the adapter tube  24  and the number and the distribution of the fins  16  around the body of the projectile  12  are identical. In the embodiment represented, there are four fins  16  and four grooves  44 , evenly distributed around the body of the projectile  12  and around the adapter tube  24 , respectively. Each of the longitudinal guide grooves  42  likewise is attached at its front end, such that the projectile can be introduced into and withdrawn from the adapter tube  24  via the front of the latter. 
   The front end of the first part  38  of the adapter tube  24  is reinforced by a segmented external ring  46  between the longitudinal external grooves  44 . 
   The second part  40  of the adapter tube  24 , situated at the back of the external ring  34 , has a uniform external diameter, slightly less than the inner diameter of the launching tube  14  from which the projectile must be fired. Accordingly, the second part  40  of the adapter tube  24  can be introduced via the open front end of the launching tube  14 , after the retaining ring  22  has been mounted on the launching tube  14 . 
   Because of the arrangement which has just been described in reference to  FIGS. 1 and 2 , it is possible to launch a projectile  12  guided by optical fibre  20  and fitted with external fins  16  which can fold but not extended inside the body of the projectile, from a launching tube  14  not provided to this end, without any modification to said tube. 
   This result is made possible due to the utilisation of an adapter tube  24  serving as interface between the projectile  12  and the launching tube  24  and due to assembly of a retaining ring  22  on the launching tube  14 , the adapter tube  24  easily able to be fixed to the retaining ring  22  by the hooking means  26 . 
   The grooves  44  formed on the part front of the adapter tube  24  are utilised to ensure the guidance of the folded fins  16  of the projectile  12 , during its launch. The trimming propulsion units  18  are then placed before the segmented external ring  46  which delimits the front end of the part front of the adapter tube  24 . The jets emitted by these propulsion units  18  then rest on said ring  46  during firing. 
   As illustrated in  FIG. 3 , the ensemble formed by the projectile  12  and by the adapter device  10  is provided to be easily transported to the launch site, where the launching tube  14  is located. 
   For this purpose, the adapter device  10  further comprises a front protective cap  48 , provided to be placed on the end front of the projectile  12 , a protective cap back  50 , provided to be placed on the back end of the adapter tube  24 , closed by the base  32 , and a transport sling  52 , which connects the protective front  48  and back caps  50 . The caps  48  and  50  form with the sling  52  mobile transport elements of the ensemble made up by the projectile  12  and its adapter tube  24 . These mobile transport elements are discarded on arrival at the launch site.