Environmental seal technology for spaced transparent armor

Abstract

The present invention is embodied in environmental seal technology incorporated into a double-paned window, the environmental seal technology comprising an inner desiccant seal and a structural spacer. The subject invention solves the problem of moisture between the window panes by keeping the internal gap dry using a desiccant system. The invention also incorporates a durable structural spacer that will not rupture under normal military vehicle loads and environmental conditions. The spacer is bonded to the window panes using pressure-sensitive adhesives, thus allowing for easy manufacture.

1 . A spaced transparent armor structure comprising:
 a first transparent laminate configured as a pane having a first face, a second face, and an edge;   a second transparent laminate configured as a pane having a first face, a second face, and an edge;   a structural spacer bonded to the second face of the first transparent laminate and to the first face of the second transparent laminate; and   a desiccant;   wherein the structural spacer has an elastic modulus greater than 300 psi;   wherein the first and second transparent laminates are spaced in a substantially parallel relationship so that an air gap is defined therebetween; and   wherein the desiccant is positioned to absorb moisture trapped in the air gap.   
     
     
         2 . The spaced transparent armor structure of  claim 1 , wherein the desiccant is contained in an inner desiccant seal that circumscribes the air gap and that extends between the second face of the first transparent laminate and the first face of the second transparent laminate. 
     
     
         3 . The spaced transparent armor structure of  claim 2 , wherein:
 the inner desiccant seal comprises a polymer binder; and   the desiccant is supported in the polymer binder.   
     
     
         4 . The spaced transparent armor structure of  claim 3 , wherein the polymer binder is selected from the group consisting of silicone foam, ethylene propylene (EPM), ethylene propylene diene (EPDM) rubber, styrene-butadiene rubber (SBR), nitrile, and polyurethanes. 
     
     
         5 . The spaced transparent armor structure of  claim 4 , wherein the polymer binder is silicone foam. 
     
     
         6 . The spaced transparent armor structure of  claim 1 , wherein the polymer binder has an elastic modulus greater than 200 psi and less than the elastic modulus of the structural spacer. 
     
     
         7 . The spaced transparent armor structure of  claim 2 , wherein the inner desiccant seal comprises at least twenty percent desiccant. 
     
     
         8 . The spaced transparent armor structure of  claim 2 , wherein the structural spacer circumscribes the inner desiccant seal. 
     
     
         9 . The spaced transparent armor structure of  claim 1 , wherein the structural spacer comprises a material selected from the group consisting of polyurethanes, polymethyl methacrylate, and metals. 
     
     
         10 . The spaced transparent armor structure of  claim 1 , wherein the desiccant is embedded in the structural spacer. 
     
     
         11 . The spaced transparent an nor structure of  claim 1 , wherein:
 the structural spacer is configured as a hollow tube; and   the desiccant is embedded within the hollow of the tube.   
     
     
         12 . The spaced transparent armor structure of  claim 1 , further comprising a film adhesive, and wherein the structural spacer is bonded to the second face of the first transparent laminate and to the first face of the second transparent laminate by means of the film adhesive. 
     
     
         13 . The spaced transparent armor structure of  claim 12 , wherein the film adhesive is a pressure-sensitive tape adhesive. 
     
     
         14 . The spaced transparent armor structure of  claim 13 , wherein the pressure-sensitive tape adhesive is an acrylic foam tape. 
     
     
         15 . The spaced transparent armor structure of  claim 1 , further comprising a gasket bonded to the edge of the first transparent laminate and to the edge of the second transparent laminate. 
     
     
         16 . The spaced transparent armor structure of  claim 15 , further comprising a sealant, and wherein the gasket is bonded to the edge of the first transparent laminate and to the edge of the second transparent laminate by means of the sealant. 
     
     
         17 . The spaced transparent armor structure of  claim 16 , wherein the sealant is selected from the group consisting of silyl modified polymer sealants, urethane sealants, polysulide sealants, silyl-terminated-polyether sealants, acrylic sealants, and silicone sealants. 
     
     
         18 . The spaced transparent armor structure of  claim 17 , wherein the sealant is a urethane sealant. 
     
     
         19 . The spaced transparent armor structure of  claim 15 , wherein the gasket extends from the second face of the first transparent laminate to the second face of the second transparent laminate. 
     
     
         20 . The spaced transparent armor structure of  claim 1 , further comprising a urethane backfill that circumscribes the structural spacer and that extends between the second face of the first transparent laminate and the first face of the second transparent laminate. 
     
     
         21 . The spaced transparent armor structure of  claim 20 , wherein the urethane backfill further extends at least partially between the structural spacer and the second face of the first transparent laminate, and at least partially between the structural spacer and the first face of the second transparent laminate. 
     
     
         22 . The spaced transparent armor structure of  claim 20 , wherein the urethane backfill further extends around the edge of the first transparent laminate and the edge of the second transparent laminate. 
     
     
         23 . The spaced transparent armor structure of  claim 1 , further comprising a frame into which the first transparent laminate and the second transparent laminate are potted.