Ordnance device for launching failure prone fragments

Abstract

The present invention is an ordnance device capable of launching discrete failure prone fragments in a coherent, controllable fashion. The described device is comprised of an explosive charge, a buffer element, a plurality of preformed failure prone fragments, and a wrap element in the described order. Buffer element separates failure prone fragments from the explosive charge so as to protect the fragments from damage by explosive detonation products and to reduce an incident pressure wave communicated into the fragments by the detonation. Wrap element further reduces the pressure within fragments by imparting a compressive pulse into the fragments thereby offsetting the negative phase of the incident pressure wave.

1 . An ordnance device comprising: 
 (a) an explosive charge;    (b) a fragment layer including a plurality of preformed failure prone fragments;    (c) a metal buffer element disposed between said explosive charge and said fragment layer, said metal buffer element configured to attenuate an incident shock communicated into said fragment layer after detonation of said explosive charge, said preformed failure prone fragments of said fragment layer being arranged in a continuous fashion along said buffer element; and    (d) a wrap element having a first layer and a second layer, said first layer disposed between said second layer and said fragment layer opposite of said buffer element, said first layer composed of a compressible material of lower density than said second layer, said second layer configured to communicate a shock into said fragment layer to further attenuate said incident shock.    
   
   
       2 . The ordnance device of  claim 1 , wherein said fragment layer further comprises a plurality of preformed inert fragments interspersed with said preformed failure prone fragments.  
   
   
       3 . The ordnance device of  claim 1 , wherein said ordnance device is cylindrically shaped.  
   
   
       4 . The ordnance device of  claim 3 , wherein said fragment layer further comprises a plurality of preformed inert fragments interspersed with said preformed failure prone fragments.  
   
   
       5 . The ordnance device of  claim 1 , further comprising: 
 (e) a second buffer element disposed between said buffer element and said explosive charge, said second buffer element compressible and less dense than said buffer element.    
   
   
       6 . The ordnance device of  claim 5 , wherein said ordnance device is cylindrically shaped.  
   
   
       7 . The ordnance device of  claim 6 , further comprising a plurality of preformed inert fragments interspersed with said preformed failure prone fragments.  
   
   
       8 . The ordnance device of  claim 5 , further comprising: 
 (f) a polymer-based intermediate layer disposed between and contacting said preformed failure prone fragments and said wrap element; and    (g) a polymer-based outer cover disposed along and contacting said second layer opposite of said first layer.    
   
   
       9 . The ordnance device of  claim 8 , wherein said ordnance device is cylindrically shaped.  
   
   
       10 . The ordnance device of  claim 9 , further comprising a plurality of preformed inert fragments interspersed with said preformed failure prone fragments.  
   
   
       11 . The ordnance device of  claim 9 , wherein said preformed failure prone fragments have a width-to-charge-diameter ratio of approximately 0.07.  
   
   
       12 . The ordnance device of  claim 9 , wherein said preformed failure prone fragments have a location dependent dimensional variability.  
   
   
       13 . The ordnance device of  claim 1 , wherein said ordnance device is linearly shaped.  
   
   
       14 . The ordnance device of  claim 13 , further comprising a plurality of preformed inert fragments interspersed with said preformed failure prone fragments.  
   
   
       15 . The ordnance device of  claim 13 , further comprising: 
 (e) a confinement structure, said explosive charge, said buffer element, said preformed failure prone fragments and said wrap element disposed within said confinement structure in referenced order so as to allow launch of said preformed failure prone fragments unimpeded by said confinement structure.    
   
   
       16 . The ordnance device of  claim 15 , wherein said preformed failure prone fragments have a location dependent dimensional variability.  
   
   
       17 . The ordnance device of  claim 15 , further comprising a plurality of preformed inert fragments interspersed with said preformed failure prone fragments.  
   
   
       18 . A method for launching a preformed failure prone fragments comprising the steps of: 
 (a) attenuating a first shock along a first surface of said preformed failure prone fragments;    (b) communicating a second shock into a second surface along said preformed failure prone fragments; and    (c) coupling said first shock and said second shock so as to reduce pressure and stress within said preformed failure prone fragments thereby avoiding mechanical failure.    
   
   
       19 . The ordnance device of  claim 2  wherein said preformed failure prone fragments have a width-to-charge-diameter ratio of approximately 0.07.  
   
   
       20 . The ordnance device of  claim 3  wherein: 
 said metal buffer element comprises a copper buffer element having a thickness of at least 0.064 inches; and    said explosive charge has a diameter of at least 4.85 inches.