Abstract: A method of joining a sintered hard alloy member 1 such as a cylindrical rod-shaped twist drill bit blank made of material whose main component is tungsten carbide to a softer metal member such as a stainless steel shank 2 includes the steps of connecting the hard alloy member 1 and the metal member 2 to separate electrodes 3 and 4, applying a longitudinally directed force couple to the hard alloy member 1 and metal member 2 to press end faces of the members together to form an electrically conductive contact region, and passing a pulse of current through electrodes 3 and 4 of sufficient energy to melt the two end face regions of the members, thereby welding them together. Preferably, the end face of the metal member has a convex conical shape.

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.

Abstract: A drill case (10) includes a case box (20) having a longitudinally elongated rectangular cross-sectional shape closeable at one transverse end thereof by a lid (23). The case includes a slidably removable longitudinally elongated drill stand base (50) having in the upper surface thereof a plurality of longitudinally disposed, laterally spaced apart grooves (51) for receiving rectangular block-shaped drill stands (60) having longitudinally spaced apart vertical bores (61) for receiving drill bits (1). Stand base (50) has protruding outwardly from opposite lateral sides thereof a pair of parallel longitudinally disposed ribs (52) which are slidably receivable in a pair of upper or lower grooves (27) and (28) formed in the inner side walls of box (20), depending on whether short or long shank drill bits are contained in stands (60).