Patent ID: 9526840
Filing Date: 2016-12-27
CPC Classification: A61M

Claim Text:
1. A drug delivery device, comprising: a body having a receptacle for a drug and a proximal end; a piston rod in the body, the piston rod having a weight associated therewith, being movable relative to the body, and being provided for expelling a portion of the drug out of the receptacle when the piston rod moves in a distal direction; a mechanism provided to drive the piston rod distally relative to the body while delivering a portion of the drug, the piston rod having a start position with respect to the mechanism prior to delivery of a first portion the drug; a device for guiding the movement of the piston rod distally relative to the body each time a portion of the drug is delivered from the receptacle until an end positioned is reached, where the device for guiding the movement of the piston rod is fixed axially relative to the body during the delivery of the drug; and a first spring in a compressed state engaged with the device for guiding the movement of the piston rod while delivering each portion of the drug, where the first spring transitions from the compressed state to a released state while moving the device for guiding the movement distally to release the piston rod so that it can move proximally from the end position and be reset back to the start position, wherein the resetting of piston rod proximally back to the start position is caused by orientating the proximal end of the body such that the weight of the piston rod in combination with gravity moves the piston rod to the start position.