a support shaft fixedly connected with said link and inserted for rotation in said fourth or fifth wall of said {HEAD ~ housing} thereby allowing {TAIL ~ said link} to pivot at said support shaft, 
a support shaft fixedly connected with said link and inserted for rotation in said fourth or fifth wall of said { HEAD ~ housing } thereby allowing { TAIL ~ said link } to pivot at said support shaft ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH