Multiple port dual diameter pumps

摘要

A multiple port, dual diameter piston fluid dispensing pump which includes multiple input and output ports accessed by rotating at least one of the pistons and a dual or multiple diameter piston or set of pistons that cooperate so that they follow each other. The dispensing piston is of smaller diameter than the pushing piston. This diameter difference permits a longer, controllable stroke to dispense micro-liters of fluid accurately.