The unit may also be provided with {HEAD ~ a traverse motor} for driving {TAIL ~ the coring bit} into an object being cored, and for withdrawing the coring bit once a core has been formed 
for driving
The unit may also be provided with { HEAD ~ a traverse motor } for driving { TAIL ~ the coring bit } into an object being cored , and for withdrawing the coring bit once a core has been formed
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL 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