Patent ID: 7654482

Claim:
A grinding machine having a grinder comprising at least one wear part and at least one adjacent part, wherein the wear part and the adjacent part are configured and arranged to be assembled and disassembled, and wherein the wear part and the adjacent part are not exposed when assembled during operation of the grinding machine, wherein one of the parts comprises a removable part that is removably mounted within an opening defined by the other of the parts, wherein the wear part and the adjacent part define facing surfaces within the opening that are subjected to wear by rotational operation of the grinding machine about a longitudinal axis, and wherein one of the parts has a number of radial projections at evenly spaced radial locations and the other of the parts has a corresponding number of radial recesses at evenly spaced radial locations within which the radial projections are received, wherein the radial projections and the radial recesses extend along radial axes that extend radially outwardly from the longitudinal axis, and wherein the wear part is engageable within the opening of the adjacent part in a plurality of distinct rotational positions, wherein the evenly spaced radial projections and the evenly spaced radial recesses enable the wear part to be removed from the opening of the adjacent part when the facing surfaces of the parts are in a first relationship relative to each other by engagement of the projections within the recesses in a first orientation, and wherein the wear part is subsequently mounted to the adjacent part within the opening by engagement of the projections within the recesses in a second orientation different than the first orientation to alter the positional relationship of the facing surfaces of the parts, wherein the wear part comprises a bushing and the adjacent part comprises an orifice plate within which the opening is formed.