said screw lock member having an opening which rotatably accommodates said lead screw therethrough and includes the recess for engaging with {HEAD ~ said key pin} of {TAIL ~ said lead} screw 
said screw lock member having an opening which rotatably accommodates said lead screw therethrough and includes the recess for engaging with { HEAD ~ said key pin } of { TAIL ~ said lead } screw
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 HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH