Anvil for a rotary cutting unit and a rotary cutting unit having such anvil
A rotary cutting unit includes a rotary cutter overlying a rotatable anvil. The anvil includes an axle, at least one anvil portion adapted to co-operate with a knife member of a rotary cutter, and a pair of load transmitting portions adapted to abut a pair of abutment members of the rotary cutter. The pair of load transmitting portions are arranged on each side of the anvil portion. A load receiving member is provided between each load transmitting portion and the anvil portion. Each of the load receiving members is connected to the axle via a bearing. Fluid cylinders apply upward forces to the load receiving members, wherein the total upward force exceeds the weight of the anvil.
1. A rotary cutting unit comprising a rotary cutting drum and an anvil arranged therebeneath;
said cutting drum comprising at least one knife member disposed between a pair of axially spaced abutment members;
said anvil comprising an axle rotatably positioned in a set of bearings, at least one rotatable anvil portion arranged opposite the at least one knife member, and a pair of load transmitting portions abutting respective ones of said abutment members and positioned axially outward of the set of bearings, and non-rotating load receiving members disposed concentrically with the axle between said at least one rotatable anvil portion and respective ones of said load transmitting members, each of said non-rotating load receiving members connected to said axle by a respective one of said bearings; and
a load applying mechanism arranged to apply to the non-rotating load receiving members a variable upward force,
wherein the load transmitting portions transmit an upward load from the load applying mechanism to the abutment members.
2. The rotary cutting unit according to claim 1 wherein said at least one knife member consists of a centrally-disposed knife member and said at least one anvil portion consists of a single anvil portion.
3. The rotary cutting unit according to claim 1 wherein said at least one knife member comprises a plurality of axially spaced knife members, and said at least one anvil portion comprises a plurality of axially spaced anvil portions.
4. The rotary cutting unit according to claim 1 wherein said at least one knife member comprises a plurality of axially spaced knife members, and said at least one anvil portion consists of a single anvil portion.
5. The rotary cutting unit according to claim 1 wherein the load applying mechanism comprises fluid-actuated cylinders engaging respective non-rotating load receiving members.
6. The rotary cutting unit according to claim 1 , wherein the pair of abutment members of the rotary cutter have a diameter larger than a surface of the rotary cutter from which a knife member protrudes.
7. The rotary cutting unit according to claim 1 , wherein the upward force is sufficient to slightly bend upward a center region of the rotatable anvil portion.
8. The rotary cutting unit according to claim 1 , wherein each non-rotating load receiving member encircles a portion of the axle.
9. The rotary cutting unit according to claim 1 , wherein the bearings are surrounded by the non-rotating load receiving members.