Metering pump

Claim 1

IN A SANITARY METERING PUMP, THE COMBINATION WITH A BASE OF A PAIR OF SHAFTS OPERATIVELY MOUNTED IN THE BASE AND HAVING SPLINED FREE END PORTIONS PROJECTING LATERALLY FROM THE BASE, A FIRST PUMP CASING MOUNTED ON THE BASE AND HAVING A CLOSED SIDE ADJACENT THE BASE AND AN OPEN SIDE FACING AWAY FROM THE BASE AND THROUGH WHICH SAID SHAFTS EXTEND, COOPERATING PUMP ROTORS UPON THE SHAFTS WITHIN SAID FIRST PUMP CASING AND TERMINATING SUBSTANTIALLY FLUSH THEREWITH AT THE OPEN SIDE THEREOF, MEANS INCLUDING A SECOND PUMP CASING HAVING A CLOSED SIDE FOR CLOSING THE FIRST PUMP CASING, SAID SECOND CASING HAVING AN OPEN SIDE REMOTE FROM THE FIRST CASING AND INTO WHICH SECOND CASING THE FREE ENDS OF SAID SHAFTS PROJECT, COOPERATING PUMP ROTORS IN THE SECOND PUMP CASING AND MOUNTED UPON THE SPLINED FREE ENDS OF SAID SHAFTS, A CLOSURE PLATE CONNECTED WITH THE SECOND PUMP CASING AND EXTENDING ACROSS SAID LAST MENTIONED PUMP ROTORS AND ACROSS THE FREE ENDS OF THE SHAFTS, MEANS FOR REMOVABLY SECURING THE CLOSURE PLATE TO THE SECOND PUMP CASING, THE SAID LAST MENTIONED PUMP ROTORS BEING FREELY ACCESSIBLE UPON REMOVAL OF THE CLOSURE PLATE FROM THE SECOND PUMP CASING, MEANS PROVIDING INLET AND OUTLET CONNECTIONS FOR THE RESPECTIVE PUMP CASINGS, THE INLET OF THE SECOND PUMP CASING BEING CONNECTED WITH THE OUTLET OF THE FIRST PUMP CASING, THE PUMP ROTORS IN THE FIRST PUMP CASING HAVING A CAPACITY IN EXCESS OF THE CAPACITY OF THE ROTORS IN THE SECOND PUMP CASING, AND MEANS PROVIDING A VALVE CONTROLLED BYPASS FROM THE OUTLET OF THE FIRST PUMP CASING TO THE INLET THEREOF.