Alternatively, such struts may constitute shutters joining to {HEAD ~ the tube body} by {TAIL ~ resilient hinges} and pivotable about such hinges between such radially inner and outer positions 
by
Alternatively , such struts may constitute shutters joining to { HEAD ~ the tube body } by { TAIL ~ resilient hinges } and pivotable about such hinges between such radially inner and outer positions
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH