US Patent 7144384 Dispenser components and methods for patient infusion device

A device for delivering fluid to a patient including an exit port assembly, a reservoir including a side wall extending towards an outlet connected to the exit port assembly, a threaded lead screw received at least partly in the reservoir and longitudinally extending towards the outlet, and a plunger secured to the lead screw and having an outer periphery linearly slideable along the side wall of the reservoir. A tube is coaxially received on the lead screw and includes a longitudinal slot, a pin extending through the lead screw and the slot of the tube, and a gear is secured to the tube for rotation therewith.