A transition or {HEAD ~ tapered portion} 50 extends from {TAIL ~ the portion} 48 to an enlarged portion, shown as a spherical cap 52 
extends from
A transition or { HEAD ~ tapered portion } 50 extends from { TAIL ~ the portion } 48 to an enlarged portion , shown as a spherical cap 52
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH