{HEAD ~ The support unit} has a receiving portion, a biasing member, and {TAIL ~ a braking unit} 
has
{ HEAD ~ The support unit } has a receiving portion , a biasing member , and { TAIL ~ a braking unit }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL