The process 6, wherein the angle of {TAIL ~ movement} about the pivot is {HEAD ~ about 60°} 
The process 6 , wherein the angle of { TAIL ~ movement } about the pivot is { HEAD ~ about 60 ° }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD