A rod support member is coupled to the base of the rod in {HEAD ~ a manner} to permit {TAIL ~ the rod} to pivot about its base 
to permit
A rod support member is coupled to the base of the rod in { HEAD ~ a manner } to permit { TAIL ~ the rod } to pivot about its base
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH