When {HEAD ~ these recesses} are indexed to face {TAIL ~ the opposed cutter bar}, such cutter elements are rendered inoperative 
are indexed to face
When { HEAD ~ these recesses } are indexed to face { TAIL ~ the opposed cutter bar } , such cutter elements are rendered inoperative
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH