Diversionary Device

Abstract

In a multi-burst diversionary device ( 10 ) containing a number of pyrotechnic cartridges ( 22 ) arranged in a series and a firing arrangement ( 14 ), a first of the cartridges is ignited by the firing arrangement, the remaining cartridges are each ignited sequentially by the flash of pressure and heat (hot gasses) produced when a previous cartridge in the series deflagrates. The device has a housing ( 12 ) defining a number of compartments ( 20 ) in which the cartridges are received. The housing defines flow paths interconnecting the compartments in series and the first compartment with the firing arrangement. Each compartment is also fluidly connected with atmosphere.

Having described my invention, I claim: 
     
         1 . A diversionary device comprising:
 a housing holding a plurality pyrotechnic cartridges arranged in series, each cartridge having a combustible fuze and a pyrotechnic charge;   a firing arrangement including a primer charge; and   the housing defining a first flow path configured to channel hot gasses (flash) given off by the primer charge onto the fuze of a first cartridge in the series only, the housing defining further flow paths configured to channel a portion of the hot gas (flash) produced on deflagration of the pyrotechnic charge in each of the cartridges upstream from a last cartridge in the series onto the fuze of an adjacent downstream cartridge.   
     
     
         2 . A diversionary device as claimed in  claim 1 , wherein the housing defines a plurality of compartments, each compartment for holding a respective one of the pyrotechnic cartridges. 
     
     
         3 . A diversionary device as claimed in  claim 2 , wherein each compartment has a fuze end and a charge end, each cartridge being located in its respective compartment with its fuze at the fuze end of the compartment and the further flow paths being configured to connect a fuze end of each compartment with the charge end of the preceding upstream compartment in the series. 
     
     
         4 . A diversionary device as claimed in  claim 3 , wherein each compartment comprises a chamber defined within the housing, the further flow paths connecting the chambers sequentially in series, a fuze end region of each chamber in the series downstream from the first chamber being connected by means of a flow path with a charge end region of the preceding upstream chamber in the series. 
     
     
         5 . A diversionary device as claimed in  claim 1 , wherein, for each pair of adjacent chambers in the series, the housing defines a flow path which interconnects the charge end region of the upstream chamber in the pair to the fuze end region of the downstream chamber in the pair and which also connects both end regions to atmosphere. 
     
     
         6 . A diversionary device as claimed in  claim 3 , wherein the housing comprises a main body portion having a central axis with compartments disposed in the main body portion about the axis, the compartments arranged so that the charge end of each compartment is located adjacent the fuze end of the next downstream chamber in the series; the housing also comprising a first end cap and a second end cap, the end caps being releasably mountable to opposite ends of the main body portion, the end caps defining the further flow paths interconnecting compartments sequentially in series. 
     
     
         7 . A diversionary device as claimed in  claim 6 , wherein the first end cap comprises a mounting for receiving a firing mechanism and defines at least part of the first flow path for fluidly connecting the primer charge with a fuze end of a first one of the compartments in the series. 
     
     
         8 . A diversionary device as claimed in  claim 1 , wherein the compartments are disposed generally in a common plane. 
     
     
         9 . A diversionary device as claimed in claim, wherein the housing comprises a main body in which the compartments are located and a firing mechanism releasably mountable to the main body, the main body having two parts releasably attachable to one another, the chambers and fluid flow paths being defined by corresponding formations in mating faces of the two parts. 
     
     
         10 . A diversionary device as claimed in  claim 1 , wherein the compartments are arranged axially in-line. 
     
     
         11 . A diversionary device as claimed in  claim 10 , wherein the housing is elongate having an upstream end and a downstream end, the firing arrangement being located at the upstream end. 
     
     
         12 . A diversionary device as claimed in  claim 11 , wherein the housing comprises at least two tubular housing members including a first tubular housing member having an end cap at an upstream end incorporating or to which is mounted the firing mechanism and a final tubular housing member having a second end cap at a downstream end; each pair of adjacent tubular housing members being releasably interconnected by an adaptor. 
     
     
         13 . A diversionary device as claimed in  claim 12 , wherein the first end cap and each of the adaptors define at a downstream end a recess which opens into the interior the adjacent downstream tubular housing member, the recess being dimensioned to receive a fuze end of a respective one of the pyrotechnic cartridges. 
     
     
         14 . A diversionary device as claimed in  claim 13 , wherein each adaptor defines at an upstream end a further recess which opens into the interior of the adjacent upstream tubular housing member for receiving a charge end of a respective one of the pyrotechnic cartridges; each adaptor farther defining a flow path fluidly connecting the recess at the downstream end and the further recess at the upstream end. 
     
     
         15 . A diversionary device as claimed in  claim 14 , wherein the adaptor flow path comprises at least one flow passage which is offset from the axial centreline of the recess. 
     
     
         16 . A multi-burst diversionary device comprising: a housing holding a plurality of pyrotechnic cartridges and a firing arrangement operatively connected with a first one of the cartridges to ignite said first one of the cartridges only, the device comprising formations for directing on to each of the remaining cartridges a portion of the hot gas given off on deflagration another of the cartridges. 
     
     
         17 . A method of operating a multi-burst diversionary device comprising a plurality of pyrotechnic cartridges each cartridge having a combustible fuze and a pyrotechnic charge, the method comprising:
 (a) using a primer charge to ignite the fuze of a first one of the cartridges; and   (b) sequentially igniting the fuzes of the remaining pyrotechnic cartridges in series by directing a portion of the hot gas produced when each cartridge deflagrates onto the fuze of another of the cartridges.