Patent ID: 7712281

Claim:
A set of building blocks useful in forming at least a portion of a wall having two or more courses, each block comprising: first and second opposed faces; first and second opposed ends extending from the first face to the second face; first and second substantially flat and opposing load bearing surfaces extending, parallel to one another, from the first end to the second end and from the first face to the second face; a pair of end core portion, one formed in the first end and the other in the second end, the end core portions extending between the first substantially flat load bearing surface and the second substantially flat load bearing surface; a half interlock protruding from the first substantially flat load bearing surface at the first end of the block, the half interlock forming at least a portion of a periphery of one of the end core portions; and at least one core portion extending into the block from the first substantially flat load bearing surface, each of the at least one core portion being spaced apart from the half interlock and including a first opening approximately flush with the first load bearing surface and without an interlock, and a second opening approximately flush with the second load bearing surface and without an interlock; wherein, when the first ends of two of the blocks are positioned adjacent one another, in a first course of the two or more courses, the half interlock of each forms an interlock portion for mating within one of the at least one core portion of a third of the blocks, but not fitting within the end core portions of half interlocks, the one of the at least core portion of the third of the blocks being positioned in a second course of the two or more courses with the second substantially flat load beating surface thereof facing the first substantially flat load bearing surface of each of the two blocks; and when the core portion of the third of the blocks mates with the interlock portion, the second substantially flat load bearing surface of the third block comes into direct contact with the first substantially flat load bearing surfaces of each of the two blocks.