Shield for explosive cutter

Abstract

A blast shield formed as a multilayer sandwich of composite material configured to provide protection to bystanders in close proximity to operation of a linear shaped charge. An exemplary embodiment may be used to shield passengers when explosively cutting an emergency door in airliners. The composite material forming a blast shield may have two types of composition: the first type contains a layer of carbon fiber cloth, a layer of natural rubber and a layer of Kevlar fiber cloth, from the inside out in order. The second type contains a layer of carbon fiber cloth, a layer of Kevlar fiber cloth and a layer of polyurethane rubber, from the inside out in order. Both types typically use epoxy resin as the bond between each layer. Through the composition of fiber and rubber, embodiments can effectively block the spread of explosive shock waves, reduce the noise, decrease the weight of protective devices, and avoid forming wounding debris. When applied on the surface of a linear shaped charge, the blast shield can limit the explosive sub-effect to the minimum, which meets the features of aircraft cabin which has limited space and multiple passengers.

1 . A blast shield, comprising:
 a non-metallic first layer disposable to substantially cover a first area encompassing a shaped explosive charge of the type that may be used to cut through an object, said first layer being formed from a material having high strength and high temperature resistance;   a non-metallic second layer sized to substantially cover said first area and disposed above said first layer, said second layer being formed from a material having outstanding elasticity; and   a non-metallic third layer sized to substantially cover said first area and disposed above said first layer, said third layer being formed from a material having high strength and high toughness, wherein:   said first layer, said second layer, and said third layer are individually sized in thickness and are configured and arranged in harmony such that said blast shield is effective to attenuate sub-effects from the detonation of said shaped explosive charge sufficient to resist damage to a human that is within a distance of about 0.4 meter of said explosive charge during said detonation.   
     
     
         2 . The blast shield according to  claim 1 , wherein:
 said first layer is formed from carbon fiber.   
     
     
         3 . The blast shield according to  claim 1 , wherein:
 said second layer is formed from natural rubber.   
     
     
         4 . The blast shield according to  claim 1 , wherein:
 said second layer is formed from polyurethane rubber.   
     
     
         5 . The blast shield according to  claim 1 , wherein:
 said third layer is formed from aramid, or aramid-based, fiber.   
     
     
         6 . The blast shield according to  claim 1 , wherein:
 said first layer is formed from carbon fiber cloth and has a thickness of about 2 mm;   said second layer is formed from natural rubber having a thickness between about 1.5 and 2 mm; and   said third layer is formed from aramid, or aramid-based, fiber cloth and has a thickness of about 1.5 mm.   
     
     
         7 . The blast shield according to  claim 6 , wherein:
 said second layer is disposed between said first layer and said third layer.   
     
     
         8 . The blast shield according to  claim 1 , wherein:
 said first layer is formed from carbon fiber cloth and has a thickness of about 2 mm;   said second layer is formed from polyurethane rubber having a thickness of about 26 mm; and   said third layer is formed from aramid, or aramid-based, fiber cloth and has a thickness of about 1.5 mm.   
     
     
         9 . The blast shield according to  claim 8 , wherein:
 said third layer is disposed between said first layer and said second layer.   
     
     
         10 . The blast shield according to  claim 1 , wherein:
 an area of said first layer is bonded to one of said second layer and said third layer by way of epoxy resin; and   an area of said second layer is bonded to the one of said first layer and said third layer by way of epoxy resin.   
     
     
         11 . The blast shield according to  claim 10 , wherein:
 an area of said first layer is bonded to said object by way of epoxy resin.   
     
     
         12 . The blast shield according to  claim 7 , wherein:
 said first layer is formed from carbon fiber cloth and has a thickness of 2.0±0.1 mm;   said second layer is formed from natural rubber having a thickness between 1.5 and 2.0 mm; and   said third layer is formed from aramid, or aramid-based, fiber cloth and has a thickness of 1.5±0.1 mm.   
     
     
         13 . The blast shield according to  claim 9 , wherein:
 said first layer is formed from carbon fiber cloth and has a thickness of 2±0.1 mm;   said second layer is formed from polyurethane rubber having a thickness of about 26 mm; and   said third layer is formed from aramid, or aramid-based, fiber cloth and has a thickness of 1.5±0.1 mm.   
     
     
         14 . The blast shield according to  claim 1 , wherein:
 said first layer comprises layers of carbon fiber cloth arranged to form a quasi-isotropic laminate; and   said third layer comprises layers of aramid, or aramid-based, fiber cloth arranged to form a quasi-isotropic laminate.   
     
     
         15 . The blast shield according to  claim 11 , wherein:
 said object is structure of an airplane; and   said shaped explosive charge is configured and arranged to cause a door opening sized to permit an emergency escape of a human from inside said airplane.   
     
     
         16 . The blast shield according to  claim 15 , wherein:
 an area of said first layer is bonded to said second layer by way of epoxy resin;   an area of said second layer is bonded to said third layer by way of epoxy resin; and   an area of said first layer is bonded to said object by way of epoxy resin.   
     
     
         17 . A blast shield, comprising:
 a non-metallic first layer disposable to substantially cover a first area encompassing a shaped explosive charge of the type that may be used to cut through structure of an airplane effective to form an emergency exit door, said first layer being formed from high strength and high temperature resistance carbon fiber cloth arranged to form a quasi-isotropic laminate having a thickness of about 2 mm, an area of said first layer being bonded to said structure by way of epoxy resin;   a non-metallic second layer sized to substantially cover said first area and being bonded to said first layer by way of epoxy resin, said second layer consisting of natural rubber; and   a non-metallic third layer sized to substantially cover said first area and being bonded to said second layer by way of epoxy resin, said third layer being formed from high strength and high toughness aramid, or aramid-based, fiber cloth arranged to form a quasi-isotropic laminate having a thickness of about 1.5 mm, wherein:   said first layer, said second layer, and said third layer are configured and arranged in harmony such that said blast shield is effective to attenuate sub-effects from the detonation of said shaped explosive charge sufficient to resist damage to a human that is within a distance of about 0.4 meter of said explosive charge during said detonation.   
     
     
         18 . A blast shield, comprising:
 a non-metallic first layer disposable to substantially cover a first area encompassing a shaped explosive charge of the type that may be used to cut through structure of an airplane effective to form an emergency exit door, said first layer being formed from high strength and high temperature resistance carbon fiber cloth arranged to form a quasi-isotropic laminate having a thickness of about 2 mm, an area of said first layer being bonded to said structure by way of epoxy resin;   a non-metallic third layer sized to substantially cover said first area and being bonded to said first layer by way of epoxy resin, said third layer being formed from high strength and high toughness aramid, or aramid-based, fiber cloth arranged to form a quasi-isotropic laminate having a thickness of about 1.5 mm; and   a non-metallic second layer sized to substantially cover said first area and being bonded to said third layer by way of epoxy resin, said second layer consisting of a rubber material, wherein:   said first layer, said second layer, and said third layer are configured and arranged in harmony such that said blast shield is effective to attenuate sub-effects from the detonation of said shaped explosive charge sufficient to resist damage to a human that is within a distance of about 0.4 meter of said explosive charge during said detonation.