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