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