Abstract: A rocker barrel usable in conjunction with a blast stream of abrasives for the cleaning of work pieces. The rocker barrel is of the shallow depth bed type and is mounted for oscillation. The rocker barrel is provided internally with rocker members which will engage both smaller work pieces, such as engine heads, and larger work pieces, such as engine blocks, to effect the tumbling of such work pieces as the rocker barrel oscillates and at the same time maintaining work pieces within the rocker barrel always within the blast stream so as to prevent the blast stream from being directed against the rocker barrel.

Abstract: Apparatus for reducing lumps of material, such as lumps of sand recovered from casting operations in metal foundries or lumps of ore and the like, including various forms of bonded abrasive grinding wheels for abrading the lumps and reducing them to particle or granular form.