{HEAD ~ Barriers} are coupled mechanically to {TAIL ~ the parallelogram members} so as to deploy when the lift is first displaced from its stowed/retracted position 
are coupled mechanically to
{ HEAD ~ Barriers } are coupled mechanically to { TAIL ~ the parallelogram members } so as to deploy when the lift is first displaced from its stowed / retracted position
HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH