a plurality of {HEAD ~ movable bows} connected to {TAIL ~ said cover}, each movable bow having a guide at each of its opposed ends, 
connected to
a plurality of { HEAD ~ movable bows } connected to { TAIL ~ said cover } , each movable bow having a guide at each of its opposed ends ,
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH