Knife device for a chopper

An apparatus for chopping material comprising a rotatable chopper disk having at least one radially disposed opening extending therethrough, a first knife holding means mounted on said disk and having a chip guiding surface located within said radial opening, said first knife holding means having a first knife engaging portion including at least two angularly disposed knife engaging surfaces, a second knife holding means mounted on said first knife holding means and having an outer wall disposed generally along the radial face of said disk, said second knife holding means having a second knife engaging portion including at least two angularly disposed knife engaging surfaces, a knife mounted between said first and second knife holding means adjacent said opening, said knife having at least one cutting edge disposed outwardly from a radial face of said disk and defined by the intersection of first and second knife edge surfaces, said knife having first and second contact surfaces, each of said contact surfaces having first and second angularly disposed surface portions for cooperative engagement with said first and second knife engaging surfaces of said first and second knife holding means, respectively, said first angularly disposed surface portion of said first contact surface extending outwardly beyond said chip guiding surface of said first knife holding means and intersecting said first knife edge surface so that the plane of said first knife edge surface is located outwardly of the plane of said chip guiding surface, said first angularly disposed surface portion of said second contact surface extending outwardly beyond said outer wall of said second knife holding means and intersecting said second knife edge surface so that the plane of said second knife edge surface is located outwardly of the plane of said outer wall of said second knife holding means, and means for securing said knife between said first and second knife holding means, whereby the location of said first and second knife edge surfaces relative to the planes of said chip guiding surface of said first knife holding means and said outer wall of said second knife holding means, respectively, substantially prevents material from penetrating between said knife and said first and second knife holding means.