Thus, {HEAD ~ rotation} of the rod 109 will pivot the levers 24 and 25 about {TAIL ~ their pivot point} to change the spacing between the roller 8 and 7 
pivot about
Thus , { HEAD ~ rotation } of the rod 109 will pivot the levers 24 and 25 about { TAIL ~ their pivot point } to change the spacing between the roller 8 and 7
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH