Belt driven knife sharpener

Claim 1

A knife sharpener, comprising: a base; a pair of grinding belts and at least two rollers supporting each of the grinding belts, the rollers supported on the base for rotation about vertical axes; motor means connected to the base and driving one of the rollers on each grinding belt such that the belts rotate in opposite directions; one roller of each belt being a support roller for knife sharpening, the two support rollers being spaced apart with a guide roller between them, the guide roller being rotationally supported on the base on a vertical axis and closely adjacent to the grinding belt at each support roller to define a narrow crevice means on each side of the guide roller for receiving a knife blade in generally horizontal orientation perpendicular to the axes of rotation of the guide roller and the support roller and twisted about a longitudinal axis of the blade to engage an upper edge of the knife blade against the guide roller and force the cutting edge of the blade against the belt; and each support roller and the guide roller including resilient cushioning sleeve means for enabling local deformation of one support roller and the guide roller by a knife blade twisted therebetween, to permit a manually adjustable degree of twisting of the knife blade and to control the degree of twisting of the knife blade in the crevice so that the depth of grinding of the cutting edge is controlled by the amount of twisting force applied to the blade as the blade is pulled horizontally through the crevice.