{HEAD ~ The driving devices} act into {TAIL ~ the ring gap}, and each of the driving devices has a separate drive 
act into
{ HEAD ~ The driving devices } act into { TAIL ~ the ring gap } , and each of the driving devices has a separate drive
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH