{HEAD ~ The insert} is pushed forward into the open jacket which is pushed away from {TAIL ~ the opening blade} permitting closure by gravity 
{ HEAD ~ The insert } is pushed forward into the open jacket which is pushed away from { TAIL ~ the opening blade } permitting closure by gravity
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH