Patent ID: 7390314

Claim:
A reservoir for use with a medication infusion device having a rotatable lead screw with uniform thread size throughout the length of the lead screw for controllably dispensing fluid from the reservoir, the reservoir comprising: a hollow reservoir barrel adapted for receiving and supporting a supply of the fluid; and a reservoir plunger slidably received into the barrel and movable within the barrel to deliver the fluid from the barrel; wherein the reservoir plunger includes at least two radially flexible legs and an integral split nut connector that comprises at least a threaded partial nut formed at the end of each leg of the plunger such that the plunger is configured to engage the uniform thread sized lead screw between the at least two legs and the threaded partial nut on each leg can simultaneously engage the lead screw when the legs are compressed radially inwards to form a whole nut on the lead screw; and wherein the at least two radially flexible legs have arched surfaces to provide flexibility in the radial direction and rigidity in the axial direction.