Patent ID: 9737658
Date: 2017-08-22
CPC Classifications: A61M

Claim:
1. A stopper arrangement for a drug delivery device, comprising a stopper, a linear actor coupled with one end to the stopper and with an opposite end to a coupling arrangement, wherein the stopper arrangement is configured to be disposed within a container of a drug delivery device, wherein a first frictional force between the coupling arrangement and the container is lower than a frictional force between the stopper and the container when the linear actor is contracting, wherein a second frictional force between the coupling arrangement and the container is greater than the frictional force between the stopper and the container when the linear actor is expanding, wherein the coupling arrangement comprises at least one wedge block tapering towards a distal direction and a conical inner ring tapering towards a proximal direction, wherein the wedge block is configured to be arranged between the inner ring and the container, wherein the inner ring is attached proximally to a proximal plate and distally to the linear actor, wherein the coupling arrangement is configured to engage to the container with the first frictional force, wherein the inner ring and wedge block are configured to engage to the container when the linear actor is expanding thus increasing the amount of friction to the second frictional force.