초록

The disclosed invention includes an improved construction of structural members such as railroad crossties, highway spin posts and highway guard posts and to construction of said members from composite wood material including elongated wood flakes and to a method for making such improved structures.

대표청구항 ▼

An elongated composite wood member having a longitudinal axis and being comprised of composite wood material, said composite wood material member comprising: a first composite wood material portion including elongated planar wood flakes intermixed with a binder and compressed to form a densified pro

An elongated composite wood member having a longitudinal axis and being comprised of composite wood material, said composite wood material member comprising: a first composite wood material portion including elongated planar wood flakes intermixed with a binder and compressed to form a densified product, said elongated wood flakes each having a longitudinal axis, the grain direction of said wood flakes being aligned parallel with said longitudinal axis of said wood flakes, said wood flakes being aligned with their longitudinal axis parallel to the longitudinal axis of the elongated member, and said planar wood flakes lying in parallel planes, and a second composite wood material portion integrally joined to said first composite wood portion, said second composite wood material portion comprising elongated planar wood flakes intermixed with a binder and compressed to form a densified product, said densified product formed by said second composite wood material portion having a density other than the density of said first portion and having strength properties different from the strength properties of said first portion, said first composite wood portion and said second composite wood portion being formed at the same time and by forming a loosely felted mat comprised of said elongated planar wood flakes intermixed with a binder, said mat including a first portion intended to form said first composite wood material portion and said mat including a second portion intended to form said second composite wood material portion, and by compressing said composite wood material mat in a press to form said first composite wood material portion and said second composite wood material portion. A method for forming an elongated solid structural member including a first structural member portion having a first density and a second structural member portion integrally joined to the first structural member portion and wherein the second structural member portion has a density greater than that of the first structural member portion, the method comprising the steps of providing elongated wood flakes having a grain direction extending generally parallel to the longitudinal axis thereof, admixing a binder with the wood flakes, forming a first mat of the resulting mixture with at least a majority of the wood flakes oriented such that the longitudinal axis thereof is parallel to the axis of the structural member to be formed from the mat, forming a second mat portion by depositing additional quantities of said resulting mixture on at least portions of said first mat with at least a majority of the wood flakes in said additional quantity being oriented such that the longitudinal axis thereof is parallel to the axis of the structural member to be formed, and compressing said first and second mat portions in a press applying sufficient pressure on the mat to bond the wood flakes together to form a densified integral compressed product.