{HEAD ~ a sensor mechanism} for scanning {TAIL ~ the ends} to determine whether each end extends parallel to the path without regard to the length of the piece being scanned; and 
for scanning
{ HEAD ~ a sensor mechanism } for scanning { TAIL ~ the ends } to determine whether each end extends parallel to the path without regard to the length of the piece being scanned ; and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH