Method of making interlocking checker bricks

A process of making a checker brick of uniform material density and substantially trapezoidal cross section comprising:

• a. relatively moving a mold and a bottom section along a lower path to bring the bottom section at least to a lower entrance of a mold cavity to complementally position spaced lower pairs of surfaces of the mold and bottom section which surfaces are spaced transversely of the lower path and which surfaces are each disposed in planes paralleling at least that portion of the lower path traversed when the surfaces of the mold and bottom section are complementally positioned;
• b. placing a quantity of brick raw material in the mold cavity and supporting it with the bottom section;
• c. relatively moving an upper section along an upper path at least to an upper entrance of the mold cavity to complementally position spaced upper pairs of surfaces of the mold and upper section which surfaces are spaced transversely of the upper path differently than the spacing of the lower pairs of surfaces of the mold and bottom section transversely of the lower path;
• d. relatively moving the upper and bottom sections toward one another while maintaining the complemental relationship of the surface pairs to compress the raw material in the mold cavity and force the raw material into intimate contact with outwardly and downwardly extending wall sections defining sides of the mold cavity between the spaced upper and lower pairs of complemental surfaces;
• e. continuing the relative movement of the upper and bottom sections until the raw material has been shaped into a checker brick configuration of substantially trapezoidal cross section and until a predetermined uniform material density has been achieved;
• and removing the configured brick having uniform material density and substantially trapezoidal cross section from the mold cavity.