Preferably, the compressor includes {HEAD ~ a delivery control mechanism} responsive to pressure in {TAIL ~ the suction passageway} to vary the effective cross sectional area of the suction passageway 
Preferably , the compressor includes { HEAD ~ a delivery control mechanism } responsive to pressure in { TAIL ~ the suction passageway } to vary the effective cross sectional area of the suction passageway
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH