Rotary vane pump with replaceable head unit

Claim 1

A PUMP ASSEMBLY COMPRISING AS READILY SEPARABLE COMPONENTS A PUMP UNIT INCLUDING AN IMPELLER ASSEMBLY THEREIN TOGETHER WITH AN END PLATE AND AN ADAPTER COLLAR SECURED TO OPPOSITE ENDS OF SAID PUMP UNIT, SAID PUMP UNIT COMPRISING A HOLLOW BODY WITH AN OPENING AT ONE END CLOSED BY SAID END PLATE AND AN END WALL AT ITS OTHER END, SAID BODY HAVING A CHAMBER IN ITS OPEN END AND A BORE THROUGH SAID END WALL COMMUNICATING WITH SAID CHAMBER, SAID IMPELLER ASSEMBLY INCLUDING AN IMPELLER SHAFT JOURNALED IN SAID WALL BORE AND HAVING ONE END EXTENDING THROUGH SAID END WALL TO THE EXTERIOR OF SAID BODY AND HAVING ITS OTHER END JOURNALED IN A CIRCULAR RECESS IN SAID END PLATE, AN IMPELLER HUB AND VANES MOUNTED ON SAID IMPELLER SHAFT IN SAID CHAMBER, SAID CHAMBER HAVING A DIAMETRICAL ENLARGEMENT AT SAID CHAMBER OPEN END, SAID END PLATE BEING RECEIVED ENTIRELY WITHIN SAID ENLARGEMENT, SAID ADAPTER COLLAR HAVING A BORE ALINED WITH SAID BODY BORE AND TERMINATING IN A DIAMETRICALLY ENLARGED RECESS, SAID IMPELLER SHAFT EXTENDING END PROJECTING INTO SAID RECESS, SAID ADAPTER COLLAR HAVING MOUNTING MEANS ON ONE END FOR ATTACHING IT TO A SUPPORT AND HAVING A PLANAR FACE ON ITS OTHER END ENGAGED BY SAID BODY END WALL, AN IMPELLER DRIVE SHAFT JOURNALED IN SAID COLLAR BORE AND HAVING ONE END TERMINATING WITHIN SAID RECESS AND BEING PROVIDED WITH A LATERALLY PROJECTING FLANGE SEATED IN SAID RECESS, SAID IMPELLER SHAFT AND SAID DRIVE SHAFT HAVING AN AXIALLY ENGAGEABLE AND DISENGAGEABLE COUPLING FOR THEIR ADJACENT ENDS WITHIN SAID RECESS, A BEARING SLEEVE IN SAID RECESS JOURNALING SAID ADJACENT ENDS, FLUID INTAKE AND FLUID EXHAUST MEANS EACH COMMUNICATING WITH SAID CHAMBER AND EACH COMPRISING REGISTERING PASSAGES IN SAID BODY AND COLLAR, A QUICK-DETACHABLE FASTENING MEANS RELEASABLY SECURING SAID PUMP UNIT TO SAID ADAPTER COLLAR AND FACILITATING REMOVAL AND REPLACEMENT OF A PUMP UNIT IN SAID PUMP ASSEMBLY.