{TAIL ~ An end conical portion} is formed at the apex of said intermediate conical portion and axially aligned therewith, with {HEAD ~ the intermediate conical portion} having a cone half angle greater than the end conical portion 
{ TAIL ~ An end conical portion } is formed at the apex of said intermediate conical portion and axially aligned therewith , with { HEAD ~ the intermediate conical portion } having a cone half angle greater than the end conical portion
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH