Reinforced mineral core for fire doors

Abstract

A mineral core for a door includes a substantially planar slab having a front face, a rear face, and top, bottom and side edges; a plurality of grooves formed in at least one of said front and rear faces, each groove having a reinforcing strip secured therein.

What is claimed is:  
     
         1 . A mineral core for a door comprising a substantially planar slab having a front face, a rear face, and top, bottom and side edges; and a plurality of grooves formed in at least one of said front and rear faces, each groove having a reinforcing strip secured therein.  
     
     
         2 . The mineral core of  claim 1  wherein said grooves and reinforcing strips extend substantially parallel to said side edges and substantially between said top and bottom edges.  
     
     
         3 . The mineral core of  claim 1  wherein each reinforcing strip is press fit in a respective one of said grooves.  
     
     
         4 . The mineral core of  claim 3  wherein each reinforcing strip is also adhesively secured within a respective one of said grooves.  
     
     
         5 . The mineral core of  claim 1  wherein said reinforcing strips are made of wood, polylaminate, MDF boards or HDF boards.  
     
     
         6 . The mineral core of  claim 1  wherein said reinforcing strips are made of glass fiber strips, ceramic fiber strips, glass fibers, ceramic fibers or paper in a matrix bonded by cement, magnesia cement, colloidal silica, colloidal alumina, potassium silicate or sodium silicate.  
     
     
         7 . The mineral core of  claim 1  wherein said grooves are formed in both said front and rear faces of said core, with a reinforcing strip in each groove.  
     
     
         8 . The mineral core of  claim 7  wherein said respective pairs of grooves on said front and rear faces lie in single planes extending through the core, parallel to said side edges.  
     
     
         9 . The mineral core of  claim 7  wherein said grooves on said front and rear faces are laterally offset from each other.  
     
     
         10 . The mineral core of  claim 1  wherein grooves are each about ⅞ inch wide and ⅛ inch deep.  
     
     
         11 . The mineral core of  claim 4  wherein said adhesive is a potassium or sodium silicate glue.  
     
     
         12 . A reinforced door construction comprising: 
 a core including a substantially planar slab having a front face, a rear face and top, bottom and side edges with rails along said top and bottom edges and stiles along said side edges; a plurality of grooves formed in at least one of said front face and said rear face; and    a reinforcing strip pressed into each of said grooves.    
     
     
         13 . The reinforced door construction or  claim 12  wherein said reinforcing strips are adhesively secured within said grooves.  
     
     
         14 . The reinforced door of  claim 13  wherein said reinforcing strips are made of wood, polylaminate, MDF boards or HDF boards.  
     
     
         15 . The reinforced door of  claim 14  wherein said reinforcing strips are made of glass fiber strips, ceramic fiber strips, glass fibers, ceramic fibers or paper in a matrix bonded by cement, magnesia cement, colloidal silica, colloidal alumina, potassium silicate or sodium silicate.  
     
     
         16 . The reinforced door of  claim 12  wherein said grooves are formed in both said front and rear faces of said core, with a reinforcing strip in each groove.  
     
     
         17 . The reinforced door of  claim 16  wherein said respective pairs of grooves on said front and rear faces lie in single planes extending through the core, parallel to said side edges.  
     
     
         18 . The reinforced door of  claim 16  wherein said grooves on said front and rear faces are laterally offset from each other.  
     
     
         19 . The reinforced door of  claim 12  wherein grooves are each about ⅞ inch wide and ⅛ inch deep.  
     
     
         20 . The reinforced door of  claim 13  wherein said adhesive is a potassium or sodium silicate glue.  
     
     
         21 . The reinforced door of  claim 12  wherein said grooves and reinforcing strips extend into said rails.  
     
     
         22 . The reinforced door of  claim 12  wherein said grooves extend substantially parallel to said side edges, at least between said top and bottom edges of said core.