A spring is supported by the bolt and urges the sleeve and {HEAD ~ locking bar} toward {TAIL ~ the outer end} of the bolt 
toward
A spring is supported by the bolt and urges the sleeve and { HEAD ~ locking bar } toward { TAIL ~ the outer end } of the bolt
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH