Patent ID: 6048183
Filing Date: 2000-04-11
Classification: F04B,F16K

Abstract:
A pump comprising:at least a first pumping chamber;a diaphragm defining a portion of the first pumping chamber;a housing having an inlet, an inlet passage leading from the inlet to the pumping chamber, an outlet and an outlet passage leading from the pumping chamber to the outlet;a first pumping member movable in the pumping chamber on an intake stroke whereby fluid from the inlet passage is drawn into the pumping chamber and a discharge stroke whereby fluid in the pumping chamber is discharged into the outlet passage;a drive for moving the pumping member on the intake and discharge strokes;a valve plate mounted in the housing and having the outlet passage extending therethrough and an outlet area adjacent the outlet passage, the outlet area being concave and in the substantial form of a portion of a sphere having a valve plate outlet radius and a valve plate outlet center point;an outlet valve carried by the valve plate and including a convex outlet valve surface adapted to cooperate with the outlet area to control flow through the outlet passage, the convex outlet valve surface being in the substantial form of a portion of a sphere having an outlet valve radius and an outlet valve center point;wherein the ratio, R, of the outlet valve radius to the valve plate outlet radius is at least 1.08, and the ratio, R.sub.1, of the difference between the outlet valve center point and the valve plate outlet center point to R is at least 0.06.