Pump

Claim 1

IN A PUMP, THE COMBINATION WHICH COMPRISES: A PUMP HOUSING FORMING A PUMPING CHAMBER; AN INLET AND AN OUTLET COMMUNICATING WITH SAID PUMPING CHAMBER, AT LEAST SAID OUTLET BEING ARRANGED SO AS TO BE GENERALLY ABOVE SAID PUMPING CHAMBER; A LIQUID SEAL FOR SEALING SAID OUTLET; PUMPING ROTOR MEANS ARRANGED IN SAID PUMPING CHAMBER FOR PERIODICALLY DIVIDING THE SAME INTO PORTIONS SO THAT THERE WILL PERIODICALLY COME INTO EXISTENCE A PUMPING CHAMBER PORTION WHICH IS IN COMMUNICATION WITH SAID OUTLET BUT OUT OF COMMUNICATION WITH SAID INLET; AND INJECTOR MEANS PASSING THROUGH SAID OUTLET FOR MIXING A COMPRESSIBLE FLUID MEDIUM WITH THE LIQUID OF SAID LIQUID SEAL AND FOR INTRODUCING THE THUS-OBTAINED MIXTURE BELOW SAID OUTLET INTO SAID LAST-MENTIONED PUMPING CHAMBER PORITON, SAID INJECTOR MEANS COMPRISING A TUBULAR ELEMENT HAVING A COMPRESSIBLE FLUID MEDIUM INLET ARRANGED ABOVE THE LEVEL OF THE LIQUID IN SAID LIQUID SEAL, A LIQUID INLET ARRANGED BELOW SAID LEVEL, AND AN OUTLET END COMMUNICATING WITH SAID OUTLET OF SAID PUMPING CHAMBER AND WHEREIN THE DOSAGE OF AIR INTRODUCED BY SAID INJECTOR MEANS INTO SAID PUMPING CHAMBER PORTION BEING SUCH AS TO DAMP PUMP NOISES WITHOUT APPRECIABLY REDUCING THE MAXIMUM OBTAINABLE VACUUM.