The end supports of the support roller for the lower belt rest on a hydraulically actuated piston which enables {HEAD ~ this support roller} to be displaced towards {TAIL ~ the other support roller} 
to be displaced towards
The end supports of the support roller for the lower belt rest on a hydraulically actuated piston which enables { HEAD ~ this support roller } to be displaced towards { TAIL ~ the other support roller }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL