Patent ID: 7882674

Claim:
A construction block for vertical stacking comprising: three generally rectangular walls of generally the same size that are spaced generally parallel to one another, two of said walls being a first outer wall and a second outer wall, each of said first and second outer walls has an inner face and an outer face, and one of said walls being an inner wall, said walls having a first short side, a second short side, a first long side and a second long side, wherein said first short sides of each of said walls are generally in the same plane, wherein said first long sides of each of said walls are generally in the same plane, wherein said second outer wall has at least one projection on its first long side and at least one recess on its second long side for receiving a similar projection, said at least one recess has a plurality of surfaces extending from said inner face to said outer face of said second outer wall; at least four generally planar webs, said webs being generally perpendicular to said walls, wherein said webs are spaced generally parallel to one another, wherein two of said webs are positioned between said first outer wall and said inner wall so as to connect said first outer wall and said inner wall, and wherein two of said webs are positioned between said second outer wall and said inner wall so as to connect said second outer wall and said inner wall; and at least one end wall having an outer face and an inner face, said at least one end wall is perpendicular to and connects said first outer wall, said second outer wall and said inner wall, wherein said at least one end wall has at least one projection and at least one recess for receiving a similar projection, said at least one recess has a plurality of surfaces extending from said inner face to said outer face of said at least one end wall.