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