As the cam member 24 moves toward {HEAD ~ the tube}, its angled interior sides 78 contact {TAIL ~ the tool holders} 32 forcing them radially into engagement with the tube 20 
As the cam member 24 moves toward { HEAD ~ the tube } , its angled interior sides 78 contact { TAIL ~ the tool holders } 32 forcing them radially into engagement with the tube 20
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH