Patent ID: 8336435

Claim:
A rotary cutting unit, comprising: a rotary cutting drum comprising at least one knife member disposed between a pair of axially spaced abutment members; a rotatable anvil comprising an axle, at least one anvil portion to co-operate with the knife member of the rotary cutting drum, and a pair of load transmitting portions to abut and contact the pair of abutment members of the rotary cutting drum, wherein the pair of load transmitting portions are arranged on each side of the at least one anvil portion; and deflection element defining a bending magnitude of the anvil, wherein the anvil includes a core and a single mantle having an interior surface contacting the core and an opposing exterior surface, wherein the exterior surface of the mantle is continuous and forms the exterior surface of the at least one anvil portion and the pair of load transmitting portions of the anvil, and the exterior surface of the mantle is substantially parallel with the exterior surface of the core across the length of the at least one anvil portion and the pair of load transmitting portions, and wherein the deflection element comprises two annular grooves in the interior surface of the mantle between the core and the mantle, a first annular groove located in a portion of the mantle forming at least a portion of a first of the pair of load transmitting portions and a second annular groove located in a portion of the mantle forming at least a portion of a second of the pair of load transmitting portions.