The control member has control surfaces which are inclined at different angles with respect to its axis, while {HEAD ~ the locking element} has {TAIL ~ control surfaces} which are complementary to the control surfaces of the control member 
The control member has control surfaces which are inclined at different angles with respect to its axis , while { HEAD ~ the locking element } has { TAIL ~ control surfaces } which are complementary to the control surfaces of the control member
OTH OTH OTH OTH 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH