Pumping method and pumps for suspensions

Claim 1

A METERING PUMP ARRANGEMENT FOR DISPENSING METERED VOLUMES OF A LIQUID SUSPENSION CONTAINING PROPORTIONATE AMOUNTS OF A SUBSTANCE AND OF A LIQUID SUSPENSION MEDIUM IN WHICH THE SUBSTANCE IS SUSPENDED, COMPRISING FIRST WALL MEANS DEFINING A FIRST PUMP CHAMBER HAVING AN INLET MEANS FOR A LIQUID SUSPENSION AND AN OUTLET MEANS, A SEPARATING CHAMBER ADJACENT SAID PUMP CHAMBER AND HAVING AN INLET, SAID FIRST WALL MEANS INCLUDING A PARTITIONING WALL BETWEEN SAID FIRST PUMP CHAMBER AND SAID SEPARATING CHAMBER HAVING A FIRST OPENING CONNECTING SAID FIRST PUMP CHAMBER AND SAID SEPARATING CHAMBER, AND ANOTHER WALL BOUNDING SAID SEPARATING CHAMBER AND FORMED WITH A SECOND OPENING; SEALING MEANS IN SAID SECOND OPENING; SECOND WALL MEANS DEFINING A SECOND PUMP CHAMBER HAVING AN INLET AND AN OUTLET FOR THE LIQUID SUSPENSION MEDIUM ONLY; A CONDUIT MEANS CONNECTING SAID OUTLET OF SAID SECOND PUMP CHAMBER WITH SAID INLET OF SAID SEPARATING CHAMBER AND INCLUDING A CHECK VALVE; AND MOVABLE PUMPING MEANS INCLUDING A FIRST PART LOCATED IN SAID FIRST PUMP CHAMBER AND IN SAID SEPARATING CHAMBER AND PASSING THROUGH SAID FIRST AND SECOND OPENINGS WHILE SLIDINGLY ENGAGING SAID SEALING MEANS, AND A SECOND PART LOCATED IN SAID SECOND PUMP CHAMBER, SAID FIRST AND SECOND PARTS BEING CONNECTED FOR SYNCHRONOUS MOVEMENT TO ALTERNATELY EFFECT DISCHARGE FROM THE RESPECTIVE PUMP CHAMBERS AND BEING CONSTRUCTED AND ARRANGED SO THAT SAID FIRST PART DISPENSES DURING A PRESSURE STROKE A METERED VOLUME OF THE LIQUID SUSPENSION FROM SAID FIRST PUMP CHAMBER AND DISPENSES A GIVEN METERED VOLUME OF THE LIQUID SUSPENSION MEDIUM FROM SAID SEPARATING CHAMBER THROUGH SAID FIRST OPENING INTO SAID FIRST PUMP CHAMBER, AND SO THAT SAID SECOND PART DISPENSES DURING THE SUCTION STROKE OF SAID FIRST PART A GIVEN METERED VOLUME OF SAID LIQUID SUSPENSION MEDIUM FROM SAID SECOND PUMP CHAMBER INTO SAID SEPARATING CHAMBER TO EFFECT FLOW OF SUSPENSION MEDIUM THROUGH SAID FIRST OPENING INTO SAID FIRST PUMP CHAMBER SO THAT THE LIQUID SUSPENSION IS PREVENTED FROM FLOWING INTO SAID SEPARATING CHAMBER AND SAID SUBSTANCE IS PREVENTED FROM CONTACT WITH SAID SEALING MEANS DURING BOTH STROKES OF SAID FIRST PART.