FIGS 2, 4, and 5 show {TAIL ~ the present invention} being practiced with {HEAD ~ an “S” type airlock} 
FIGS 2 , 4 , and 5 show { TAIL ~ the present invention } being practiced with { HEAD ~ an “ S ” type airlock }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD