{HEAD ~ A hole} in the pivoting ball top extension accepts {TAIL ~ a pin}, and the hole is situated with respect to the frame such that the pin will be against the frame when the pivoting ball support face is in its first position 
{ HEAD ~ A hole } in the pivoting ball top extension accepts { TAIL ~ a pin } , and the hole is situated with respect to the frame such that the pin will be against the frame when the pivoting ball support face is in its first position
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH