{HEAD ~ A second base plate} 51 is rotatably mounted on {TAIL ~ the first base plate} 50 having a centrally disposed pin 52 extending into an opening 53 in the base plate 50 
is rotatably mounted on
{ HEAD ~ A second base plate } 51 is rotatably mounted on { TAIL ~ the first base plate } 50 having a centrally disposed pin 52 extending into an opening 53 in the base plate 50
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH