The release member releases a force pulling the retractable unit when {HEAD ~ the retractable unit} is moved to {TAIL ~ the closed position} 
is moved to
The release member releases a force pulling the retractable unit when { HEAD ~ the retractable unit } is moved to { TAIL ~ the closed position }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL