Each of two springs is connected to one of the levers and to the housing and moves {TAIL ~ the pressing roller} away from the driven roller when {HEAD ~ the pressure} in the chamber drops below a predetermined value 
Each of two springs is connected to one of the levers and to the housing and moves { TAIL ~ the pressing roller } away from the driven roller when { HEAD ~ the pressure } in the chamber drops below a predetermined value
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH