Reciprocating antirotation pump

摘要

A pump for pumping discrete liquid volumes is provided with an anti-rotation construction to prevent a nut mated to a rotating head screw from rotating when the lead screw is rotated. The anti-rotation construction comprises a set of rails that slideably fit within a mating set of tracks. The pump also can include a variable homing position for a pump piston having at least two different homing positions.