초록 ▼

The invention relates to a metering pump assembly having a reciprocable pump element with an adjustable stroke. The pump assembly includes a hydraulic system with two adjustable volume chambers, one chamber being associated with the pump element and the other with a displaceable element having an el

The invention relates to a metering pump assembly having a reciprocable pump element with an adjustable stroke. The pump assembly includes a hydraulic system with two adjustable volume chambers, one chamber being associated with the pump element and the other with a displaceable element having an electromagnetic drive. Adjustable throttle means are provided between the two chambers for adjusting the stroke of the pump element in accordance with the setting of the throttle means.

대표청구항 ▼

A metering pump unit comprising a first pumping means having a movable pumping element which provides first and second oppositely expanding and contracting chambers on opposite sides thereof, inlet and outlet valve means for said first chamber to effect the flow of fluid into and out of said first c

A metering pump unit comprising a first pumping means having a movable pumping element which provides first and second oppositely expanding and contracting chambers on opposite sides thereof, inlet and outlet valve means for said first chamber to effect the flow of fluid into and out of said first chamber upon the respective expansion and contraction thereof, second pumping means and an expansible chamber, parallel supply and return fluid paths between said expansible chamber of said second pumping means and said second chamber of said first pumping means, adjustable throttle means in said supply path for varying the quantity of a fluid delivered to said second chamber per time unit during the forward stroke of said second pumping means, and one way valve means in said return path.