{HEAD ~ The braking unit} applies {TAIL ~ frictional force} to the stopper when the cover is opened 
applies
{ HEAD ~ The braking unit } applies { TAIL ~ frictional force } to the stopper when the cover is opened
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH