A first portion of {TAIL ~ the pressurized fluid} is directed downwardly for {HEAD ~ impringement} upon the material being drilled to pick up and remove dust and cuttings from the vicinity of the cutting cones 
A first portion of { TAIL ~ the pressurized fluid } is directed downwardly for { HEAD ~ impringement } upon the material being drilled to pick up and remove dust and cuttings from the vicinity of the cutting cones
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH