At the same time, {TAIL ~ the tightening system} affixes {HEAD ~ the clamping lock} inside the beam 
At the same time , { TAIL ~ the tightening system } affixes { HEAD ~ the clamping lock } inside the beam
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH