frictionless plastic bearing material not only interposed between said metal swivel plates with {HEAD ~ its opposite sides} engaging {TAIL ~ opposite plates} for bearing and spacing purposes but, for said axial aligning and centering purposes, also curved to conform to the circular curvature of said V shaped race in said one metal plate, 
engaging
frictionless plastic bearing material not only interposed between said metal swivel plates with { HEAD ~ its opposite sides } engaging { TAIL ~ opposite plates } for bearing and spacing purposes but , for said axial aligning and centering purposes , also curved to conform to the circular curvature of said V shaped race in said one metal plate ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH OTH OTH