Patent ID: 7510319

Claim:
A mixing apparatus for concrete including: a mixing drum supported for rotation about a longitudinal axis, the drum having a closed end defined by a drum head and an open end to receive batch materials to be mixed; a first, generally helical, mixing blade disposed within the drum and extending towards the drum head; and a second blade extending at an angle from the first, generally helical, mixing blade toward the drum head, the second blade being adapted upon mixing rotation of the drum to push/mechanically transfer material from the bottom of the drum near the drum head and to elevate the material for cascading discharge toward the open end of the drum and downward toward the area of largest diameter of the drum and wherein; the first, generally helical, mixing blade develops in a counter-clockwise direction from an open end of the drum towards the drum head and the second blade extends in a clockwise direction towards the drum head; and wherein the first, generally helical, mixing blade defines a spillway formation adjacent the second blade and wherein the height of the second blade is greater than the height of the adjoining mixing blade at the point of intersection of the first, generally helical, mixing blade and the second blade, thereby to define a side wall of the spillway formation.