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