US Patent 8696407 Cutting tool sharpener

Method (300) and apparatus (100) for sharpening a cutting tool (114, 132, 204, 210, 216). A flexible abrasive belt (116, 116A, 116B, 162, 172) with a selected linear stiffness and an abrasive surface (128A, 128B) of selected abrasiveness level is driven (304) in a selected direction along a selected plane between a first support (122) and a second support (118). In some embodiments, the cutting tool is presented (306, 308) in contacting engagement against the abrasive surface to induce torsion of the belt (140, 144, 148) out of the selected plane to conform to a cutting edge (138, 168, 178, 207, 208, 213, 214, 215) of the cutting tool. In further embodiments, presentation of the cutting tool against the abrasive surface of the belt (306, 308) induces bending of the belt out of said selected plane at a radius of curvature (169, 179) determined in relation to said linear stiffness to shape a side surface (164, 166, 174, 176) of the cutting tool with said radius of curvature.