{HEAD ~ The pressure blade} ensure {TAIL ~ adequate contact} between the advancing cover material and the outer surface of the counter shaft 
{ HEAD ~ The pressure blade } ensure { TAIL ~ adequate contact } between the advancing cover material and the outer surface of the counter shaft
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH