Cassette knife for chipper

Abstract

A knife assembly for a wood chipper has a cassette, a top blade holder, and a trapezoidal cross-section double-edge blade. The cassette is of profiled cross-section, with a full-width proximal section, a stepped-down blade holder support surface on an intermediate section, and a blade support surface on a distal or tip section. A proximally and downward sloping surface extends from a distal edge of the blade holder support surface to the blade support surface. The blade has substantially flat upper and lower surfaces so as to avoid structure which is susceptible to snapping or splitting under the stresses normally encountered in a chipping operation. One edge of the trapezoidal blade is exposed and extends forward of the cassette and the blade holder. The tapered ground surface that defines the concealed edge of the blade faces against the sloping surface of the cassette. Molten babbitt is poured through openings in the blade holder to form babbitt shims filling the space between the concealed blade sloping surface and the sloping surface of the cassette. Thus, the blade is supported both from beneath and at the concealed ground or tapered surface. Further, the babbitting provision permits precise positioning and adjustment of knife projection.