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