FIG 3 further illustrates the provision of a notch 90 formed by {HEAD ~ shoulders} on {TAIL ~ the adjacent facing circumferential ends} of the segments 80 
on
FIG 3 further illustrates the provision of a notch 90 formed by { HEAD ~ shoulders } on { TAIL ~ the adjacent facing circumferential ends } of the segments 80
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH