Patent attributes
A medication delivery pen is provided having a lead screw with an enlarged portion at a first end thereof and an end longitudinally opposite the first end in contacting engagement with a plunger of a medication cartridge. The lead screw is selectively axially displaceable by a user when selectively administering a predetermined dosage amount of medication for injection into a patient. The medication delivery pen also includes a driver coaxially disposed about the lead screw; and, a reset ring non-rotatably disposed on the driver and axially slidable thereon and therealong. The reset ring is axially movable with respect to the driver when a dosage amount is set by a user of the medication delivery pen. The reset ring engages the enlarged portion of the lead screw upon a predetermined extent of relative axial movement between the reset ring and the lead screw. With this arrangement, the reset ring advantageously prevents setting a dose on a medication delivery pen that is greater than the medication which is available.
