Fluid metering device

Claim 1

A CENTRIFUGAL PUMP COMPRISING A CASING, AN IMPELLER ROTATABLY MOUNTED IN THE CASING, A FIXED VALVE MEMBER LOCATED WITHIN THE CENTRAL RECESS IN THE IMPELLER, A MOVING VALVE MEMBER ALSO LOCATED WITHIN THE CENTRAL RECESS FOR BOTH AXIAL AND ANGULAR MOVEMENT RELATIVE TO THE FIXED VALVE MEMBER ABOUT THE IMPELLER AXIS TO DEFINE A RADIALLY DIRECTED VARIABLE AREA ORIFICE WITHIN THE RECESS, A LINK PIVOTALLY CONNECTED AT ONE POSITION OF ITS LENGTH TO THE FIXED VALVE MEMBER AND AT ANOTHER POSITION ALONG ITS LENGTH TO THE MOVING VALVE MEMBER TO LOCATE THE MOVING VALVE MEMBER FOR MOVEMENT RELATIVE TO THE FIXED MEMBER IN A FIXED PATH COMBINING AXIAL AND ANGULAR MOVEMENT SUCH THAT FOR MOVEMENT OF THE MOVING VALVE MEMBER IN ONE DIRECTION ALONG THE FIXED PATH THE DIMENSIONS OF THE ORIFICE INCREASE BY BOTH AXIAL AND ANGULAR MOVEMENTS AND FOR MOVEMENT OF THE MOVING VALVE MEMBER IN THE OTHER DIRECTION ALONG THE FIXED PATH THE DIMENSION OF THE ORIFICE DECREASE BY BOTH AXIAL AND ANGULAR MOVEMENTS.