Projectiles

Abstract

A projectile ( 10 ) arranged to be launched from a launcher ( 12 ), the projectile comprising a source of compressed gas ( 1 ) and control means ( 23 ) for controlling the release of the compressed gas, in which the control means ( 24 ) is arranged so as to release the compressed gas in response to the launching of the projectile ( 10 ) from the launcher ( 12 ). Typically, the control means ( 24 ) is a valve, arranged such that the application of gas pressure from the launcher ( 12 ) is required in order to release the compressed gas, but the application of gas pressure must abate before the compressed gas is released. Thus, the compressed gas may only be released once the projectile ( 10 ) has cleared the launcher ( 12 ).

1 . A projectile arranged to be launched from a launcher, the projectile comprising a source of compressed gas and control means for controlling the release of the compressed gas, in which the control means is arranged so as to release the compressed gas in response to the launching of the projectile from the launcher. 
     
     
         2 . The projectile of  claim 1 , in which the control means is arranged to release the compressed gas in response to the application of gas pressure by the launcher as part of the launching of the projectile. 
     
     
         3 . The projectile of  claim 1 , in which the control means is arranged to release the compressed gas in response to the acceleration of the projectile upon launch. 
     
     
         4 . The projectile of  claim 1 , in which the control means is arranged such that the release of the compressed gas is delayed until after the projectile has cleared the launcher. 
     
     
         5 . The projectile of  claim 4  in which the control means is arranged to release the compressed gas in response to the application of gas pressure by the launcher as part of the launching of the projectile, and in which the control means is arranged such that the application of gas pressure is required in order to release the compressed gas, but the application of gas pressure must abate before the compressed gas is released. 
     
     
         6 . The projectile of  claim 5 , in which the control means comprises a valve comprising a diaphragm and a piercing body, with the control means being arranged such that application of gas pressure by the launcher forces the piercing body into the diaphragm so as to pierce the diaphragm. 
     
     
         7 . The projectile of  claim 6 , in which the piercing body comprises a blocking element, which blocks the release of compressed gas while gas pressure is applied to the projectile by the launcher, but which is arranged so as to allow the release of compressed gas on abatement of the applied gas pressure. 
     
     
         8 . The projectile of  claim 7 , in which the blocking element comprises a valve body mounted in a bore in the projectile through which gas pressure can be applied by the launcher in use, the bore having a first cross section at a first position occupied by the valve body when the piercing element is piercing the diaphragm; and a second cross section at a second position occupied by the valve body without the application of gas pressure by the launcher, the second cross section being larger than the first cross section. 
     
     
         9 . The projectile of  claim 8 , in which the valve body fills the first cross section so as to block the bore at the first position but is smaller than the second cross section and hence allows the passage of compressed gas in the second position. 
     
     
         10 . The projectile of  claim 1 , in which the projectile comprises a bore extending from the source of compressed gas to the rear of the projectile, there forming an exit for the compressed gas, in which the bore comprises an expansion chamber at the exit, of increased cross section compared to the bore adjacent thereto. 
     
     
         11 . The projectile of  claim 10 , in which the expansion chamber tapers towards the exit. 
     
     
         12 . The projectile of  claim 10 , in which the bore is provided with ridges, arranged so as to cause vortices in the compressed gas as it is released from the projectile. 
     
     
         13 . A projectile launching system comprising a compressed gas launcher and a projectile according to  claim 1 .