Radial staging for reentry compressor

Claim 1

A FLUID PUMP OF THE DRAG TYPE COMPRISING A CASING HAVING AN INLET OPENING FOR CONNECTION TO A SOURCE OF FLUID TO BE PUMPED AND AN OUTLET OPENING FOR DIRECTION OF THE PUMPED FLUID TO A POINT OF UTILIZATION, SAID CASING HAVING A RADIAL FACE FORMED INTERNALLY THEREOF CHARACTERIZED BY HAVING FORMED THEREIN INNER AND OUTER CONCENTRICALLY DISPOSED ANNULAR PUMPING DUCTS COMMUNICATING WITH SAID INLET AND OUTLET PORTS, A ROTOR IN SAID CASING HAVING A DRIVE SHAFT CONNECTED THERETO, SAID ROTOR HAVING A RADIAL FACE INCLUDING ANNULAR RECESSES DISPOSED IN CONCENTRIC RELATION FOR REGISTRY WITH SAID PUMPING DUCTS, SAID ROTOR HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED SLOTS EACH EXTENDING ACROSS SAID ANNULAR RECESSES, AND VANE MEANS IN SAID SLOTS TO FORM WITH SAID RECESSES A PLURALITY OF IMPELLER POCKETS IN EACH RESPECTIVE RECESS, AND INTERCONNECTING PASSAGE MEANS IN SAID CASING DISPOSED BETWEEN SAID PUMPING DUCTS TO INTERCONNECT SAID PUMPING DUCTS IN STAGE FLOW RELATION, SAID RADIAL FACE OF SAID CASING BEING RECESSED ADJACENT SAID INTERCONNECTING PASSAGE MEANS, AND A THIN COVER MEMBER RECEIVED AND SEATED IN SAID INTERCONNECTING OF SAID CASING FACE TO OVERLIE SAID INTERCONNECTING PASSAGE MEANS AND THE ADJACENT END PORTIONS OF SAID INNER AND OUTER DUCTS, THEREBY TO INSURE CONTINUITY OF FLUID FLOW WITH MINIMUM FLOW LOSS.