This is accomplished by progressively reducing {HEAD ~ the oscillatory pivotal movement} of the carrier 22 as the tool 17 is continuously advanced into {TAIL ~ the workpiece} 
This is accomplished by progressively reducing { HEAD ~ the oscillatory pivotal movement } of the carrier 22 as the tool 17 is continuously advanced into { TAIL ~ the workpiece }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL