a frame mounted to said {HEAD ~ housing} for {TAIL ~ vertical movements} and located adjacent to said floor opening 
for
a frame mounted to said { HEAD ~ housing } for { TAIL ~ vertical movements } and located adjacent to said floor opening
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH