Centrifugal pumps and the like

Claim 1

A CENTRIFUGAL PUMP, COMPRISING A CASING HAVING AXIALLY SPACED OPPOSED WALLS AND A PERIPHERAL WALL DEFINING A PUMPING CHAMBER, SAID PERIPHERAL WALL HAVING A CIRCUMFERENTIALLY EXTENDING RIDGE EXTENDING AROUND A SUBSTANTIAL PORTION OF THE PERIPHERY OF SAID CIRCUMFERENTIAL WALL AND PROJECTING INWARDLY TOWARD THE AXIS OF THE CASING, THE OPPOSITE PERIPHERAL ENDS OF SAID RIDGE TAPERING GRADUALLY OUTWARDLY TOWARD SAID CIRCUMFERENTIAL WALL IN THE CIRCUMFERENTIAL DIRECTION OF SAID RIDGE, SAID RIDGE HAVING A TOP SURFACE HAVING AN AXIAL WIDTH SUBSTANTIALLY LESS THAN THE AXIAL SPACING OF SAID SIDE WALLS, SAID RIDGE AND SPACED SIDE WALLS DEFINING BETWEEN THEM CIRCUMFERENTIALLY EXTENDING CONCAVE GROOVES COEXTENSIVE WITH SAID RIDGE, AN IMPELLER IN THE PUMPING CHAMBER OF SAID CASING ROTATABLE ABOUT THE AXIS OF SAID CASING, SAID IMPELLER HAVING OPPOSED AXIALLY SPACED WALLS WITH THE PERIPHERAL PORTIONS OF THE INWARDLY OPPOSED SURFACES THEREOF FLARED SMOOTHLY OUTWARDLY TOWARD THE RESPECTIVE ADJACENT OPPOSED WALLS OF SAID CASING, SAID IMPELLER FURTHER HAVING BLADES BETWEEN SAID WALLS, THE RADIALLY OUTER TRAILING ENDS OF SAID BLADES HAVING A SMOOTH CONCAVE RECESS IN THE CENTRAL PORTION THEREOF, SAID OPPOSED WALLS OF SAID CASING CURVING SMOOTHLY FROM ADJACENT THE PERIPHERY OF SAID IMPELLER INTO SAID GROOVES, AND A DISCHARGE BRANCH ON SAID CASING AND OPENING INTO SAID PUMPING CHAMBER OF SAID CASING ONLY THROUGH THE TOP SURFACE OF SAID RIDGE ALONG A PORTION OF THE LENGTH OF SAID RIDGE, SAID PORTION OF THE LENGTH OF THE RIDGE BEING AT RADIAL DISTANCES FROM THE CENTER OF THE CASING WHICH ARE LESS THAN THE RADIAL DISTANCES OF THE REMAINDER OF THE TOP SURFACE FROM THE CENTER OF THE CASING, WHEREBY SAID IMPELLER WALLS AND BLADES, SAID OPPOSED CASING WALLS, THE CONCAVE GROOVES IN SAID PERIPHERAL WALL AND SAID RIDGE COACT TO PRODUCE A PAIR OF FLUID FLOWS WHICH ARE OUTWARDLY DIVERGING FROM THE PERIPHERY OF SAID IMPELLER AND THEN INWARDLY CONVERGING AT THE SIDES OF SAID RIDGE, AND SAID FLOW DEFINING A LOWER ENERGY CENTRAL ZONE AT SAID DISCHARGE OPENING IN SAID TOP SURFACE OF SAID RIDGE.