CPC A61M 5/31511 (2013.01) [A61M 5/2033 (2013.01); A61M 5/31583 (2013.01)] | 16 Claims |
1. A delivery assembly for a drug delivery device, the delivery assembly comprising:
a reservoir having a tubular housing extending along a longitudinal axis and having a delivery opening at a distal end;
a plunger disposed within the reservoir in engagement with the housing;
a flexible plunger rod comprising a spring having a predetermined preload amount and being operably coupled to the plunger; and
a feeding mechanism coupled to the flexible plunger rod and configured to drive the flexible plunger rod along the longitudinal axis of the housing to drive the plunger towards the distal end, the feeding mechanism including a drive gear assembly having a central opening for the spring to extend therethrough, the central opening including a thread configured to engage the spring such that rotation of the drive gear assembly relative to the spring causes the spring to move longitudinally through the drive gear assembly,
wherein the thread includes a shim that is configured to extend between adjacent coils of the spring.
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