Corrosion resistant centrifugal pump

Claim 1

A CORROSION RESISTANT CENTRIFUGAL PUMP COMPRISING A PUMP HOUSING AN IMPELLER SHAFT ROTATABLY SUPPORTED WITHIN SAID HOUSING ABOUT AN AXIS OF ROTATION, AN IMPELLER FORMED OF CORROSION RESISTANT HARD-TO-FORM MATERIAL SECURED TO ONE END PORTION OF SAID IMPELLER SHAFT AND HAVING BOTH PUMPING VANES AND EXPELLER VANES FORMED THEREON OF SIMILAR CONSTRUCTION, SAID VANES BEING DEFINED BY SURFACES FORMED ALONG CONTINUOUS STRAIGHT LINES TO FACILITATE FORMATION OF THE IMPELLER AND EACH HAVING A LONGITUDINAL AXIS WHICH IS OFFSET WITH RESPECT TO SAID AXIS OF ROTATION, THE SIDE SURFACES OF SAID PUMPING VANES AND EXPELLER VANES BEING DISPOSED IN SUBSTANTIALLY PARALLEL PLANES, SAID PLANES EXTENDING SUBSTANTIALLY NORMALLY TO SAID AXIS OF ROTATION, EACH OF SAID PUMPING AND EXPELLER VANES INCLUDING END SURFACES EXTENDING BETWEEN SAID SIDE SURFACES TO DEFINE THEREWITH PASSAGES OF GENERALLY ELONGATED RECTANGULAR CROSS-SECTIONAL CONFIGURATION, ONE END SURFACE OF EACH OF SAID PUMPING AND EXPELLER VANES DEFINING A PRESSURE FACE, EACH OF SAID PRESSURE FACES OF THE PUMPING AND EXPELLER VANES HAVING A RADIALLY EXTENDING MID PORTION SUBSTANTIALLY MIDWAY BETWEEN THE ADJACENT SIDE SURFACES OF THE VANES, SUCH RADIALLY EXTENDING MID PORTIONS LYING SUBSTANTIALLY ALONG A LINE PASSING THROUGH SAID AXIS OF ROTATION, A FIRST SEALING MEANS SUPPORTED BY SAID IMPELLER SHAFT AND CONNECTED FOR ROTATION THEREWITH, A SECOND SEALING MEANS SUPPORTED BY SAID HOUSING AND COOPERATING WITH SAID FIRST SEALING MEANS TO PROVIDE A SEAL THEREWITH, MEANS FOR SHIFTING SAID IMPELLER SHAFT AXIALLY THEREOF FOR MOVING SAID SEALING MEANS AWAY FROM ONE ANOTHER TO BREAK THE SEAL THEREBETWEEN, MEANS NORMALLY URGING SAID SEALING MEANS INTO SEALING RELATIONSHIP WITH ONE ANOTHER, SAID SEALING MEANS EACH BEING FORMED OF CORROSION RESISTANT MATERIAL, THE PORTIONS OF SAID HOUSING ADJACENT SAID IMPELLER BEING SPACED THEREFROM AND ALSO BEING FORMED OF CORROSION RESISTANT MATERIAL SUCH THAT THE PORTIONS OF THE PUMPING MEANS WHICH ENGAGE THE PUMPED FLUID RESIST CORROSION DURING USE.