Automatic drill bit re-pointing apparatus and method

Abstract

A method and apparatus for automatically re-pointing twist drill bits includes a drill support mechanism including means for rotatably and axially translatably holding the shank of a drill bit, and a fluted portion receiver for supporting the fluted front cutting portion of the drill bit. The apparatus also includes an optical sensor unit which views the tip and blade part of the drill bit with the drill support mechanism in an off-line position, i.e., rotated away from a grinding wheel station. Responsive to error correction servo command signals received from a comparison of the actual orientation of drill bit cutting lips with a desired pre-determined template position, rotary and linear actuators in the drill support mechanism rotate the drill bit to the proper angular orientation, and advance the bit axially to a pre-determined protrusion length. Also, command signals to the fluted portion receiver elevate the drill bit point to a pre-determined elevation, whereupon a linear actuator cylinder linked via a pivot pin to the drill support mechanism rotates the latter to thereby place the properly oriented drill bit in contact with grinding wheels of a sharpening unit. After each of the grinding wheels has sequentially contacted the cutting edges and point of the drill bit and resurfaces the contacted areas to a desired sharpness, the linear actuator cylinder is used to rotate the drill support mechanism to the off-line position, whereupon a shank retainer is pivoted vertically away from the drill bit shank, allowing the re-conditioned bit to be removed and replaced with another bit to be re-pointed.