Pump

Claim 1

IN A PUMP ASSEMBLY COMPRISING A DIAPHRAGM PUMP HAVING A PUMPING CHAMBER, A WORK CHAMBER, A VALVECONTROLLED INLET AND VALVE-CONTROLLED OUTLET FOR SAID WORK CHAMBER, AND A PUMPING PORT FOR ADMITTING A PULSATING LIQUID PUMPING FLUID TO SAID PUMPING CHAMBER TO FLEX THE DIAPHRAGM AND EFFECT PUMPING OF WORK FLUID THROUGH SAID WORK CHAMBER; AND A ROTARY PUMP FOR SUPPLYING A PULSATING PUMPING FLUID TO SAID PUMPING PORT; THE IMPROVEMENT WHEREIN SAID PUMPING CHAMBER INCLUDES MEANS TO VENT GASEOUS FLUID FROM SAID PUMPING CHAMBER COMPRISING A PASSAGE IN THE TOP OF THE PUMPING CHAMBER, A SHAFT INTERSECTING SAID PASSAGE TO SEPARATE THE PASSAGE INTO A LOWER BRANCH AND AN UPPER BRANCH, SAID SHAFT INCLUDING POCKET MEANS OPERABLE UPON DISPLACEMENT OF SAID SHAFT BETWEEN FIRST AND SECOND POSITIONS TO ALTERNATIVELY REGISTER RESPECTIVELY WITH THE TOP OF SAID LOWER BRANCH AND THE BOTTOM OF SAID UPPER BRANCH, AND MEANS TO INTRODUCE LIQUID PUMPING FLUID INTO SAID UPPER BRANCH, AND MEANS TO DISPLACE SAID SHAFT SUCCESSIVELY BETWEEN SAID FIRST POSITION WHEREIN SAID POCKET RECEIVES A PREDETERMINED VOLUME OF FLUID FROM THE TOP OF SAID LOWER BRANCH, AND SAID SECOND POSITION WHEREIN SAID POCKET RECEIVES A PREDETERMINED VOLUME OF LIQUID PUMPING FLUID FROM THE BOTTOM OF SAID UPPER BRANCH, WHEREBY ANY GASEOUS FLUID IN SAID PUMPING CHAMBER IS TRANSFERRED TO SAID UPPER BRANCH UPON DISPLACEMENT OF SAID SHAFT FROM SAID FIRST POSITION TO SAID SECOND POSITION AND PUMPING FLUID IS TRANSFERRED FROM SAID UPPER BRANCH TO SAID CHAMBER UPON DISPLACEMENT OF SAID SHAFT FROM SAID SECOND POSITION TO SAID FIRST POSITION.