Abstract: A rotary self-sharpening knife comprises two identical half-knives each having a cutting edge on one face, the half knives being arranged with at least part of the peripheries of their other faces in contact, and means for urging the half knives together. In use the half knives are driven at different angular speeds so that there is slight relative movement of the half knives which produces a rubbing action between the peripheries of the half knives to maintain the cutting edges of the half knives sharp. The invention also relates to an assembly incorporating the inventive self-sharpening knife, and a machine for processing a product.

Abstract: An assembly for use in a machine for processing sheet or similar material comprising a rotatable tool and an opposing part between which the sheet material is fed and each mounted on a respective block and positionally adjustable relative thereto to vary the spacing between the tool and its opposing part, each block being movable in a direction transversely of the feed direction, and means for driving the tool and its opposing part each comprising a pinion supported on the block and meshing with a toothed shaft extending transversely of the direction of sheet material feed, wherein the toothed shafts are positioned so as to operate as feed rollers for feeding sheet material to the tool and its opposing part.