Detonation interrupter

Abstract

A disruptor ( 10 ) has a plastics barrel ( 12 ) cast from unreinforced polyurethane so that only plastic deformation of the barrel occurs during initiation of a cartridge ( 18 ) a discharge of a water charge ( 24 ).

1 - 17 . (canceled) 
     
     
         18 . A disruptor comprising
 a barrel   a breech mechanism at a breech end of the barrel to receive a cartridge of deflagrating propellant;   a charge of liquid,   seals in the barrel to prevent the liquid charge leaking from the muzzle end of the barrel and from contacting the cartridge; wherein   the barrel is cast in a mould from plastics material whereby, when the cartridge is initiated to drive the charge from the barrel, the material of the barrel is distorted plastically but is not fractured.   
     
     
         19 . A disruptor as claimed in  claim 18 , in which the plastics material is a polyurethane. 
     
     
         20 . A disrupter as claimed in  claim 18 , in which the plastics material has a static failure strength of between 20 and 60 MPa. 
     
     
         21 . A disrupter as claimed in  claim 20 , in which the plastics material has a static failure strength of between 30 and 50 MPa. 
     
     
         22 . A disrupter as claimed in  claim 18 , in which the barrel is between 200 and 600 mm long, has an inner diameter of between 20 and 40 mm and a wall thickness of between 5 and 15 mm. 
     
     
         23 . A disrupter as claimed in  claim 22 , in which the barrel is between 300 and 500 mm long, has an inner diameter of between 25 and 35 mm and a wall thickness of between 7 and 12 mm. 
     
     
         24 . A disriptor as claimed in  claim 23 , in which the barrel is between 380 and 420 mm long, has an inner diameter of between 26 and 30 mm and a wall thickness of between 7 and 9 mm. 
     
     
         25 . A disrupter as claimed in  claim 18 , in which the barrel has a mass of between 200 and 600 g. 
     
     
         26 . A disrupter as claimed in  claim 25 , in which the barrel has a mass of between 300 and 500 g. 
     
     
         27 . A disrupter as claimed in  claim 26 , in which the barrel has a mass of between 380 and 420 g. 
     
     
         28 . A disrupter as claimed in  claim 18 , in which the barrel withstands a propulsive pressure generated at its breech end of between 500 and 700 bar applied for up to 10 milliseconds. 
     
     
         29 . A disrupter as claimed in  claim 18 , in which the liquid charge has a mass of between 100 and 150 g. 
     
     
         30 . A disruptor as claimed in  claim 18 , in which the plastics material is unreinforced by any thing that is not poured with the plastics material into the mould. 
     
     
         31 . A disrupter as claimed in  claim 18 , in which the barrel has a cast thread for connection of a breech cap. 
     
     
         32 . A method of making a disrupter, comprising the steps of casting a barrel from thermoplastic polymer in mould; cooling the polymer so that it solidifies and removing it from the mould; inserting a deflagrating propellant cartridge at a breech end of the barrel; connecting on a breech cap; inserting a water projectile, and providing electrical connections to the cartridge for firing same. 
     
     
         33 . A method as claimed in claim  16 , in which the mould is provided with an internal thread formation at one end of the mould, said removing step including unscrewing the barrel from the mould; and said connecting of the breech cap comprises screwing it onto the thread on the barrel.