The apparatus of {HEAD ~ the present invention} also includes means for driving {TAIL ~ the cutting tool assembly} into and out of engagement with the tube 
The apparatus of { HEAD ~ the present invention } also includes means for driving { TAIL ~ the cutting tool assembly } into and out of engagement with the tube
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH