As the rod moves in {TAIL ~ the direction} of the secondary extrudate 42 it contacts the primary extrudate 41 and thereafter causes {HEAD ~ the primary extrudate} to move toward the secondary extrudate 
As the rod moves in { TAIL ~ the direction } of the secondary extrudate 42 it contacts the primary extrudate 41 and thereafter causes { HEAD ~ the primary extrudate } to move toward the secondary extrudate
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH