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