A drill bit having thermally stable PCD cutting elements includes a matrix body element having a plurality of spaced cutting elements supported in a body of matrix material such that a substantial portion of the cutter is above the body matrix and a minor portion is received within the body matrix. The...http://www.google.es/patents/US4673044?utm_source=gb-gplus-sharePatente US4673044 - Earth boring bit for soft to hard formations
