摘要 |
A rotary grinding disc in an apparatus for refining fibrous pulp material, comprising a plurality of arcuate grinding plate segments disposed annularly about the disc and supported thereon by means of wedge-shaped tongues projecting from the segment plates and dovetailed into grooves of corresponding profile in the disc, the wedge-shaped tongues and dovetail grooves decreasing in width from an outer radial portion toward an inner radial portion, or vice versa, for wedging the plate segment into the disc. The plate segments may be additionally secured against displacement by the effect of the centrifugal force during rotation of the disc by means of a peripheral ring surrounding the disc and engaging the wedged tongues. |