The third arm 48, via its lobe section 50, permits {TAIL ~ linear movement} in the directions of {HEAD ~ the Y axis} 
The third arm 48 , via its lobe section 50 , permits { TAIL ~ linear movement } in the directions of { HEAD ~ the Y axis }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD