The casing defines spaced apart internal frustoconical surfaces positioned to engage {HEAD ~ corresponding surfaces} of {TAIL ~ the segments} in the same axial direction 
of
The casing defines spaced apart internal frustoconical surfaces positioned to engage { HEAD ~ corresponding surfaces } of { TAIL ~ the segments } in the same axial direction
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH