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