Patent ID: 7497395

Claim:
A grinding mill comprising: a) a grinding section comprising a substantially cylindrical structure which defines a grinding chamber and which is mounted to be able to rotate about a longitudinal center axis of said cylindrical structure in a forward direction; b) a lift section which is positioned within said structure and which comprises a plurality of lift elements which are mounted in said structure and arranged to travel with said structure in a generally circular path in a forward direction; c) at least some of said lift elements being adjacent lift elements located in side-by-side relationship so as to be located at intervals longitudinally spaced from one another, each of said adjacent lift elements having a contact surface comprising a middle contact surface portion and two oppositely positioned side surface contact portions which at least in part slant from said middle contact surface portion from one another in longitudinal directions in a manner that pairs of said adjacent lift elements have facing pairs of side surface contact portions which face one another and slant downwardly toward one another as pairs of valley surfaces to form a related valley region which has a substantial valley alignment which is aligned in a forward direction generally parallel to the circular forward path of travel of the lift elements; whereby as rocks and rock fragments tumble from an upper located side of the rotating lift section, the valley surfaces that form the valley region have a channeling effect in directing a path of travel of rocks and rock fragments into valley regions so that there is a wedge action against the facing valley surfaces so as to be capable of introducing sheer forces exerted on wedged rocks as other rocks and rock fragments fall from an upper forward location in the grinding chamber and impact the rocks and rock fragments to exert the sheer forces and cause greater fracturing of the rocks and rock surfaces.