a cam surface located on {HEAD ~ an exterior portion} of {TAIL ~ the tieback member} in engagement with an inner side of the locking member 
of
a cam surface located on { HEAD ~ an exterior portion } of { TAIL ~ the tieback member } in engagement with an inner side of the locking member
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH