In a second embodiment, {HEAD ~ a pair} of {TAIL ~ holes} are formed through the base plate of one of the scroll members 
In a second embodiment , { HEAD ~ a pair } of { TAIL ~ holes } are formed through the base plate of one of the scroll members
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH