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