Patent ID: 7223311

Claim:
A method of making wallboard comprising the steps of: forming a continuous slab of wallboard having opposed face surfaces bordered by a pair of longitudinal side edges; forming longitudinal recessed areas along said side edges on a first face of the wallboard; forming a first desired cut length or wallboard from the wallboard slab whereby the side edges of the cut length are connected by opposed lateral edges; forming recessed areas in said opposed lateral edges of the first face of said cut wallboard length by moving the lateral edges of the cut length of wallboard through a series of laterally spaced roller sets aligned with each of said lateral edges the roller sets having vertically spaced rollers; adjusting the vertical spacing of the vertically spaced rollers of the roller sets in response to the thickness of the wallboard being processed; and adjusting the size of the wallboard lengths and simultaneously adjusting the lateral spacing of the sets of vertically spaced rollers to accommodate the size of the cut wallboard lengths.