Patent ID: 6837453

Claim:
A shredder comprising: at least one rotor rotatable about an axis and having an outer surface formed generally as a surface of revolution about the axis, the outer surface defining a succession of radially outwardly protruding circumferential ribs spaced apart axially along the rotor such that valleys are defined between the ribs; a counter knife arranged in opposition to the outer surface of each rotor, a space being defined between the counter knife and the outer surface of the rotor for passage of material being shredded, the counter knife defining a succession of teeth spaced apart in the axial direction of the rotor such that recesses are defined between the teeth, each tooth being axially aligned with one of the valleys in the rotor's outer surface; a plurality of V-cutters affixed to the outer surface of each rotor, each V-cutter having a pair of cutting edges forming a radially outwardly protruding V-shaped cutting vertex, the V-cutters being spaced apart axially such that each recess in the counter knife meshes with at least one V-cutter and such that each V-cutter partially overlaps in the axial direction with at least one other axially adjacent V-cutter; and a plurality of flat cutters affixed to the outer surface of each rotor, each flat cutter having a substantially straight cutting edge that is generally parallel to the axis of the rotor, each flat cutter being aligned in the axial direction with one of the valleys in the rotor's outer surface, whereby the flat cutters are positioned to work in conjunction with the counter knife to cut material disposed between two axially adjacent V-cutters.