said lead screw is provided with a key pin for engagement with a recess provided on the screw lock member and for inhibiting said lead screw from rotation when said {HEAD ~ key pin} is engaged with {TAIL ~ said recess} 
is engaged with
said lead screw is provided with a key pin for engagement with a recess provided on the screw lock member and for inhibiting said lead screw from rotation when said { HEAD ~ key pin } is engaged with { TAIL ~ said recess }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL