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