Patent ID: 7287445

Claim:
A sharpening apparatus for manually obtaining a microstructure of microteeth along the cutting edge of a blade having two faces that at their terminus having been sharpened forming two facets that intersect to create an elongated edge at the junction of the two facets, said apparatus comprising a member which is mounted to be non-rotating during sharpening, said member having a generally non-abrasive hardened surface, a precision angle guide mounted in intimate proximity to said member, said precision angle guide having an elongated two-dimensional planar knife-face contacting guide surface to be of sufficient size to establish the plane of the blade and along which a face of the blade can be stroked to position a facet of the blade in sustained moving contact with said hardened surface, said planar guide surface being at an angle to said hardened surface at the location of contact of the facet with said hardened surface, and said precision angle guide and said member when attached together forming a generally rigid assembly wherein said angle remains fixed and constant whereby during repeated strokes of the facet against said hardened surface at the constant angle alternating stresses of sufficient magnitude are created along the blade edge to harden the blade edge and make the blade edge more brittle and prone to fracture and fragment causing small sections of the blade edge to drop off leaving a microscopic microtooth-like structure along the blade edge.