Pumps

Claim 1

A PUMP WHICH COMPRISES, IN COMBINATION, A PUMP BODY PROVIDED WITH A CAVITY HAVING A CYLINDRICAL INNER SURFACE AND RESPECTIVE SUCTION AND DELIVERY ORIFICES PROVIDED AT THE ENDS OF SAID PUMP BODY RESPECTIVELY, SAID INNER SURFACE CONSISTING OF TWO HALF CIRCULAR CYLINDRICAL PORTIONS OF THE SAME DIAMETER DISPOSED OPPOSITE EACH OTHER, WITH THEIR CONCAVITIES TURNED TOWARD EACH OTHER AND JOINED TOGETHER BY TWO PARALLEL FLAT PORTIONS, A SHAFT HAVING ITS MEAN LINE IN THE FORM OF A HELIX DISPOSED IN SAID BODY COAXIALLY THEREWITH, THE LENGTH OF THIS SHAFT BEING AT LEAST EQUAL TO THE PITCH OF SAID HELIX, THE CROSS SECTION OF THIS SHAFT BEING THE SAME OVER THE LENGTH OF SAID SHAFT AND HAVING THE SAME WIDTH IN ALL DIRECTIONS, SAID SHAFT INCLUDING, AT ITS RESPECTIVE ENDS, CYLINDRICAL TRUNNIONS JOURNALLED IN SAID BODY COAXIALLY THEREWITH, A MULTIPLICITY OF ADJACENT PLATES TRANSVERSE TO THE AXIS OF MULTIPLICITY OF ADJACENT PLATES TRANSVERSE TO THE AXIS OF CENTRAL APERTURE HAVING TWO LONGER SIDES PARALLEL TO EACH OTHER AND PERPENDICULAR TO THE DIRECTION OF THE FLAT PORTIONS OF THE PUMP BODY INNER SURFACE, SAID TWO SIDES BEING AT A DISTANCE FROM EACH OTHER EQUAL TO THE ABOVE MENTIONED WIDTH OF THE CROSS SECTIONS OF SAID SHAFT, ALL OF SAID PLATES HAVING THEIR APERTURES ENGAGED ON SAID SHAFT, THE OUTLINE OF EACH OF SAID PLATES BEING CIRCULAR, EACH OF SIAD PLATES BEING PROVIDED WITH AT LEAST ONE SLOT PARALLEL TO SAID LAST MENTIONED DIRECTION, ALL OF SAID SLOTS HAVING THE SAME WIDTH, AT LEAST ONE ROD CARRIED BY SAID BODY IN FIXED POSITIONE AND FITTING SLIDABLY IN SAID SLOTS, AND A FLUDTIGHT FLEXIBLE TUBULAR SHEATH SURROUNDING ALL OF SAID PLATES SO AS TO FORM THEREWITH A DEFORMABLE STRUCTURE HOUSED IN SAID CAVITY WITH A SLIDING FIT, THE ENDS OF SAID SHEATH BEING SECURED IN A FLUDTIGHT MANER RESPECTIVELY TO THE SUCTION ORIFICE AND TO THE DELIVERY ORIFICE OF SAID PUMP BODY.