{HEAD ~ The holes} are covered by {TAIL ~ the wrap} of the other scroll member for the majority of the operational cycle of the scroll compressor 
are covered by
{ HEAD ~ The holes } are covered by { TAIL ~ the wrap } of the other scroll member for the majority of the operational cycle of the scroll compressor
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH