Diaphragm pumps

Claim 1

A DIAPHRAGM PUMP COMPRISING A PUMP BODY HAVING AN OPERATING CHAMBER THEREIN, A DIAPHRAGM DISPOSED ACROSS AND MOVEABLE IN SAID CHAMBER, A FLUID INLET AND A FLUID OUTLET IN SAID BODY BOTH COMMUNICATING WITH SAID CHAMBER ON ONE SIDE OF SAID DIAPHRAGM, A NON-RETURN VALVE IN EACH SAID INLET AND OUTLET, AN OPERATING FLUID STORAGE CHAMBER IN SAID BODY, A CYLINDER CONNECTING SAID STORAGE CHAMBER TO SAID OPERATING CHAMBER ON THE SIDE OF SAID DIAPHRAGM REMOTE FROM SAID INLET ANT OUTLET, A CONSTANTLY ROTATING PISTON SLIDABLY DISPOSED IN SAID CYLINDER WITH A PORTION EXTENDING THROUGH THE STORAGE CHAMBER TO THE EXTERIOR OF SAID BODY, SAID CYLINDER HAVING A SLOT EXTENDING AXIALLY IN THE WALL THEREOF FROM SAID STORAGE CHAMBER TOWARDS SAID OPERATING CHAMBER, AND SAID PISTON HAVING A PASSAGE EXTENDING THEREIN FROM SAID OPERATING CHAMBER AND OPENING INTO THE CYLINDRICAL SURFACE OF SAID PISTON WITHIN THE LENGTH OF SAID SLOT TO ENGAGE THEREWITH ONCE IN EACH COMPLETE ROTATION OF SAID PISTON SO THAT WHEN SAID CHAMBERS AND PASSAGE ARE FILLED WITH OPERATING FLUID, AXIAL RECIPROCATION OF SAID PISTON WILL CAUSE MOVEMENT OF SAID DIAPHRAGM TO DRAW IN SAID EJECT FROM SAID OPERATING CHAMBER THE FLUID BEING DELIVERED BY THE PUMP AND ROTATION OF SAID PISTON WILL CAUSE SAID PASSAGE TO COMMUNICATE WITH SAID SLOT ONE IN EACH PISTON ROTATION WHEN THE PISTON IS FURTHEST FROM THE DIAPHRAGM TO PERMIT OPERATING FLUID TO FLOW FROM THE STORAGE CHAMBER TO THE OPERATING CHAMBER.