Void containing structural member

Abstract

A void containing structural member and method of fabrication that provides for structural elements, such as beams, columns and rafters of varying shapes containing voids within the structure. In one embodiment, cellulosic materials are used, a flange type of beam configuration is provided, which includes internal longitudinally extending voids.

1 . A beam comprising:
 at least two longitudinally extending sheet layers; and   an inner structure between the sheet layers defining at least one longitudinally extending void.   
     
     
         2 . The beam of  claim 1  wherein the inner structure includes a longitudinally and horizontally extending corrugated structure and the voids are defined by at least one of the longitudinally extending sheet layers and the inner structure. 
     
     
         3 . An I-beam, comprising:
 a top flange;   a bottom flange;   wherein at least one of the top and bottom flanges including a first longitudinally extending sheet layer and a second longitudinally extending sheet layer;   a core layer positioned between the first and second sheet layers; and   wherein a longitudinally extending voids are defined between the core layer and each of the first and second sheet layers.   
     
     
         4 . The I-beam of  claim 3  wherein the core layer is made of a shaped cellulosic fiber material. 
     
     
         5 . The I-beam of  claim 3  wherein the core layer is corrugated and is formed of a shaped compressed cellulose fiber material. 
     
     
         6 . The I-beam of  claim 3  wherein the top and bottom layers are adhered to the core layer. 
     
     
         7 . The beam of  claim 1  wherein the beam is curved from one longitudinal end to the other. 
     
     
         8 . The beam of  claim 1  wherein the beam is straight from one longitudinal end to the other. 
     
     
         9 . The beam of  claim 1  wherein the beam has more than one curve from one longitudinal end to the other. 
     
     
         10 . The beam of  claim 1  further comprising an insulation material positioned within at least one void. 
     
     
         11 . The beam of  claim 1  further comprising a conduit positioned within at least one void. 
     
     
         12 . The beam of  claim 1  further comprising a ventilation duct positioned in at least one void. 
     
     
         13 . A beam comprising:
 a first and second outer layer of flat fiberboard material;   a first and second diagonal layer of flat fiberboard material secured between the first and second outer layers, wherein the first and second diagonal layers have a cutout through their center to them to pass through one another.   
     
     
         14 . The beam of  claim 13 , wherein a third and fourth outer layer of flat fiberboard material are attached to the first and second outer layers for additional strength. 
     
     
         15 . The beam of  claim 13 , further comprising a top and bottom flange, each flange comprising a stressed skin outer layer of flat fiberboard material, securing the third and fourth outer layers to the stressed skins of the flange. 
     
     
         16 . The beam of  claim 15 , wherein the top and bottom flanges and the first and second outer layers and first and first and second diagonal layers are bendable into a selected curved shape. 
     
     
         17 . The beam of  claim 16 , wherein the curved shape is a compound curve. 
     
     
         18 . The beam of  claim 13 , wherein the top and bottom flange comprises holes.