{HEAD ~ Apparatus} 8 wherein said locking means comprises {TAIL ~ a centrifugal lock} operable above a given angular velocity of said sections to effect said locking action 
{ HEAD ~ Apparatus } 8 wherein said locking means comprises { TAIL ~ a centrifugal lock } operable above a given angular velocity of said sections to effect said locking action
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH