US Patent 7967795 Cartridge interface assembly with driving plunger

A cartridge interface assembly including a driving plunger including an outer shaft, and a driver including an inner shaft, the inner shaft mating with an intermediate shaft, the intermediate shaft mating with the outer shaft, so that the shafts are movable telescopically with respect to one another, wherein rotation of the driver causes the driving plunger to advance in a direction away from the driver.