All three illustrated plate type swivels for rotationally supporting {HEAD ~ an article} on {TAIL ~ a base} broadly comprise: a pair of plates and plate spacing and centering means 
All three illustrated plate type swivels for rotationally supporting { HEAD ~ an article } on { TAIL ~ a base } broadly comprise : a pair of plates and plate spacing and centering means
OTH OTH OTH OTH OTH OTH OTH OTH OTH 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