Positioning arm 60 is attached at {HEAD ~ one end} to {TAIL ~ an adjustable pivot} 62 
Positioning arm 60 is attached at { HEAD ~ one end } to { TAIL ~ an adjustable pivot } 62
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH