A slidable tubular insert is carried within the principal conduit member and moves from {HEAD ~ an opened and closed position} to open or close an opening in the principal conduit member and permit {TAIL ~ a formed article} to move within 
A slidable tubular insert is carried within the principal conduit member and moves from { HEAD ~ an opened and closed position } to open or close an opening in the principal conduit member and permit { TAIL ~ a formed article } to move within
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH