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