CPC A61M 5/3134 (2013.01) [A61M 5/20 (2013.01); A61M 5/2033 (2013.01); A61M 5/31511 (2013.01); F16F 9/16 (2013.01); F16F 9/3228 (2013.01); F16F 9/3481 (2013.01); F16F 9/361 (2013.01); A61M 2005/2086 (2013.01); A61M 2005/3143 (2013.01); A61M 5/3243 (2013.01)] | 19 Claims |
1. An injection device for drug delivery, the injection device comprising:
a container for storing a drug, the container comprising a stopper movably disposed in the container for expelling the drug;
an injection drive mechanism comprising a plunger for acting on the stopper and an energy source for exerting a force on the plunger to cause the plunger to move in a distal direction to act on the stopper to expel the drug, the force causing the plunger to accelerate to a velocity prior to acting on the stopper; and
a damping mechanism for reducing the velocity of the plunger prior to acting on the stopper, the damping mechanism comprising energy absorbing material disposed on the plunger such that at least a portion of a proximally-facing surface of the energy absorbing material contacts at least a portion of a distally-facing surface of the plunger prior to any movement of the plunger in the distal direction,
wherein, prior to any movement of the plunger in the distal direction, a distally-facing surface of the energy absorbing material is spaced from a proximally-facing surface of the stopper.
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