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