This invention relates to the restoration of drill bit buttons or like objects and has particular application to restoration of the tungsten carbide buttons set as a spaced array in the head of a button drill bit.
Restoration of a drill button entails the removal of metal around the button to expose more of the button, and the sharpening of the button so that it presents a rounded exposed end. A traditional approach is to mount the drill bit in an adjustable vice and then to polish the button with a grinder fitted with a concave diamond burr. A more recent innovation involves mounting the bit on a slowly rotating turntable under a rapidly rotating sharpening tool of pulley-like configuration. Swedish patent application 7701534-5 by Karlsson discloses substantially the converse of this concept, viz mounting the bit on a rapidly rotating turntable under a fixed, more conventional concave burr.