The typical prior art atmosphere vent 16 is replaced by {HEAD ~ the expanded vent} 18 in {TAIL ~ the present invention} 
in
The typical prior art atmosphere vent 16 is replaced by { HEAD ~ the expanded vent } 18 in { TAIL ~ the present invention }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL