Briely stated, the present invention provides {HEAD ~ a bit assembley} for {TAIL ~ a rotary drill} having, a source of fluid under pressure 
for
Briely stated , the present invention provides { HEAD ~ a bit assembley } for { TAIL ~ a rotary drill } having , a source of fluid under pressure
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH