A frame support structure having {HEAD ~ four frame engaging members} is automatically displaced to a frame receiving {TAIL ~ position} 
A frame support structure having { HEAD ~ four frame engaging members } is automatically displaced to a frame receiving { TAIL ~ position }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL