{HEAD ~ the extension member} is pivotably attached about {TAIL ~ the rotary shaft} between the first position and the second position, 
is pivotably attached about
{ HEAD ~ the extension member } is pivotably attached about { TAIL ~ the rotary shaft } between the first position and the second position ,
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH