Laminated, variable density, structural wood products and method for making the same

Claim 1

A uniformly thick integral structural wood truss comprising a plurality of strips of wood, said plurality of strips comprising a plurality of groups of strips, at least one of said groups of strips defining a first chord, at least another of said groups of strips defining a second chord, and others of said groups of strips defining a plurality of web members, said strips being stacked and arranged flatwise with strips of different groups being interleaved, the strips defining each group being superimposed on each other, said strips being interleaved so that predetermined superimposed areas of the strips of each of said groups are interleaved with predetermined superimposed areas of the strips of another group, said strips defining said first chord being spaced apart from said strips defining said second chord, said groups of strips defining said web members interconnecting said chords, each of at least some of said groups having at least one portion constituted by superimposed areas of the strips of that group not interleaved with strips of any other group so that the assembly of stacked strips has a plurality of interleaved portions and a plurality of non-interleaved portions, each of said strips being of substantially uniform thickness throughout its length, said superimposed strips being glued to each other and pressure-consolidated, sustantially without extrusion of the wood, in a direction substantially perpendicular to the planes of the strips sufficiently to consolidate the interleaved portions to the thickness of the remaining portions, said truss being of substantially uniform thickness so that said consolidated truss has predetermined portions of a first density and other predetermined portions of greater than said first density.

Claim 3

The method for making a uniformly thick integral structural wood truss which comprises a. applying glue to the side faces of a plurality of strips of wood of substantially uniform thickness throughout their length, said plurality of strips comprising a plurality of groups of strips, at least one of said groups of strips defining a first chord, at least another of said groups of strips defining a second chord, and others of said groups of strips defining a plurality of web members for interconnecting said chords, b. stacking said strips flatwise while interleaving strips of different groups to provide an assembly of stacked, interleaved strips, the strips defining each group being superimposed on each other, the strips being interleaved so that predetermined superimposed areas of the strips of each of said groups are interleaved with predetermined superimposed areas of the strips of another group, said strips being so stacked and interleaved that said strips defining said first chord are spaced apart from said strips defining said second chord, with said groups of strips defining said web members interconnecting said chords, c. each of at least some of said groups having at least one portion constituted by superimposed areas of the strips of that group not interleaved with strips of any other group so that the assembly of stacked strips has a plurality of interleaved portions and a plurality of non-interleaved portions, and d. applying pressure across the opposite surfaces of the assembly of stacked strips in a direction substantially perpendicular to the planes of the strips and in magnitude predetermined to press and consolidate, without substantial plastic flow of the wood, the interleaved strips portions to the same thickness as the non-interleaved strip portions to thereby provide the interleaved portions with densities greater than the densities of the non-interleaved portions, e. said pressure applying to all portions of the assembly clamping pressure sufficient adherently to unite the strips by setting of the glue interfaces therebetween.

Claim 4

The method for making a uniformly thick integral structural wood truss which comprises a. applying glue to the side faces of a plurality of strips of wood of substantially uniform thickness throughout their length, said plurality of strips comprising a plurality of groups of strips, at least one of said groups of strips defining a first chord, at least another of said groups of strips defining a second chord, and others of said groups of strips defining a plurality of web members for interconnecting said chords, b. stacking said strips flatwise while interleaving strips of different groups to provide an assembly of stacked, interleaved strips, the strips defining each group being superimposed on each other, the strips being interleaved so that predetermined superimposed areas of the strips of each of said groups are interleaved with predetermined superimposed areas of the strips of another group, said strips being so stacked and interleaved that said strips defining said first chord are spaced apart from said strips defining said second chord, with said groups of strips defining said web members interconnecting said chords, c. each of at least some of said groups having at least one portion constituted by superimposed areas of the strips of that group not interleaved with strips of any other group so that the assembly of stacked strips has a plurality of interleaved portions and a plurality of non-interleaved portions, and d. applying pressure across the opposite surfaces of the assembly of stacked strips in a direction substantially perpendicular to the planes of the strips and in magnitude predetermined to press and consolidate, without substantial plastic flow of the wood, the interleaved strips portions to the same thickness as the non-interleaved strip portions to thereby provide the interleaved portions with densities greater than the densities of the non-interleaved portions, e. said pressure applying to all portions of the assembly clamping pressure sufficient adherently to unite the strips by setting of the glue interfaces therebetween.