Patent ID: 7677965

Claim:
A method of controlling throughput speed and chop quality of a rotary chopper that includes a rotary chopper element extending laterally across a material supply path with a plurality of knife blades mounted thereon, the method comprising providing an active counter knife assembly for such rotary chopper, said active counter knife assembly including a chopper grate assembly having a grate portion mounted generally parallel to the rotary chopper element across the material supply path to define a material flow path between said grate portion and the rotary chopper element, said grate portion including a plurality of spaced slots therealong, said slots extending generally transversely across the grate portion in general alignment with the direction of material flow along the material flow path, a rotatable shaft, having a shaft rotation axis therethrough, positioned generally beneath and parallel to said grate portion and having a plurality of knife elements mounted thereon at positions generally alignable with said slots of said grate portion, said rotatable shaft rotatably movable about its shaft rotation axis, said knife elements of said rotatable shaft and said slots of said grate portion being coordinately sized to permit said knife elements to project and move through said slots as said rotatable shaft is caused to rotate about its shaft rotation axis, a drive mechanism operatively connected to said rotatable shaft and operable to rotatably drive said rotatable shaft about its shaft rotation axis, operating said drive mechanism to rotate said rotatable shaft about its shaft rotation axis in a desired direction at a desired speed, wherein said chopper grate assembly further includes a concave pan construction with opposed sides, wherein said grate portion extends between said opposed sides of said concave pan construction, wherein said adjustment mechanism includes first and second end plates, wherein said rotatable shaft is connected extending between said first and second end plates for journaled rotatable movement about said shaft rotation axis, wherein said first and second end plates are connected to respective ones of said opposed sides of said concave pan construction at respective swivel points, said swivel points defining an engagement positioning axis for said end plates offset from and generally parallel to said shaft rotation axis, wherein said adjustment mechanism is operable to effect swiveled movement of said first and second end plates and said rotatable shaft extending therebetween about said engagement positioning axis, whereby the position of said rotatable shaft relative to said grate portion of said chopper grate assembly is variably adjustable, the method further including operating said adjusting mechanism to position said rotatable shaft to a desired position relative to said grate portion of said chopper grate assembly.