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