Pumping apparatus using a stepping motor

摘要

A precision-delivery and precision-pressure piston pump is actuated by a cam controlled by a finestep stepping motor. The initial delivery pressure is precisely regulated by fixing the commencement of the delivery stroke at the cam with the aid of the stepping motor, as well as the time required for this delivery. Delivery is also regulated very precisely, for example in a ratio of 1 to 1000 by controlling the delivery stroke with the aid of the stepping motor. The pump is of use in particular in high-pressure liquid-phase chromatography.