Abstract: A cutting apparatus including a grinder for sharpening knives in the cutting assembly is disclosed. The cutting apparatus includes a mouth for delivering the material to be cut to a cutting position, a cutting drum having at least one knife having a cutting edge, the cutting drum having a drive system and being rotatable about an axis. A grinder is described for removing material from the cutting edge of a knife, the grinder brought into contact with the cutting edge with a movement in a first direction substantially parallel to the axis of rotation of the cutting drum and with a movement in a second direction substantially parallel to the axis of rotation of the cutting drum, the grinder configured to move in the first direction at a first speed and move in the second direction at a second speed, the first speed different to the second speed.

Abstract: A cutting apparatus including a grinder assembly for grinding and sharpening the knives in the cutting assembly is disclosed. The cutting apparatus comprises, a mouth defined by a jaw assembly for delivering the material to be cut to a cutting position at the mouth, a cutting drum having at least one knife the, or each, knife having a cutting edge, the cutting drum having drive means therefor and being rotatable about an axis arranged substantially parallel to the mouth such that the cutting edge of the at least one knife is arranged substantially perpendicular to the material to be cut.