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