Patent ID: 7744025
Filing Date: 2010-06-29
Classification: B02C

Abstract:
1. A grinding machine for grinding material that includes a combination of hard material and soft material, comprising a rotatable knife assembly and an orifice plate having a grinding surface and a series of outer primary grinding orifices that cooperate with the knife assembly to grind material supplied to the grinding surface, wherein the orifice plate includes an inner section having a plurality of spaced apart collection passages extending therethrough that are larger than the primary grinding orifices and are designed to collect hard material, wherein the outer primary grinding orifices are located in an outer section of the orifice plate located radially outward of the collection passages, and wherein the inner section of the orifice plate further includes an inner orifice section having a plurality of secondary grinding orifices that are smaller than the collection passages and are located inwardly of the primary grinding orifices and between the collection passages.