Patent ID: 6257414
Filing Date: 2001-07-10
Classification: B07B,B27N

Abstract:
A roller sifting or dispersing machine for the classification or dispersing of wood chips, fibers, or similar materials, the roller sifting or dispersing machine comprising:at least one roller set composed of several rollers aligned axially parallel and having a same rotation direction;a roller bed formed by the rollers, the roller bed extending longitudinally at a right angle to the rollers and being provided with an input end for introduction of the material to be processed and an output end for coarse material, each of the rollers having an upper side which turns toward the output end;each of the rollers comprising a plurality of annular grooves, the annular grooves being axially equi-spaced and separated by annular crosspieces forming an outer generating surface of each of the rollers, the annular crosspieces of one roller being arranged opposite the annular grooves of an adjoining roller thus forming in a top view onto the roller bed openings for the passage of chips, which openings having a substantially closed circumference,wherein the annular grooves and the annular crosspieces are located in planes perpendicularly to a roller axis, and the outer generating surface of each annular crosspiece includes circumferentially aligned teeth having a rotation direction leading tooth flanked shape steeper than a tooth back flank inclined to a base of a following tooth side, whereby axially the annular crosspiece teeth of a roller form a gradient that is opposite to that of the adjoining roller but includes a same gradient height.