Patent ID: 9457149
Filing Date: 2016-10-04
CPC Classification: A61M

Claim Text:
1. A back-end device of an auto-injector adapted to be attached to a packaged syringe, the back-end device comprising: a chassis, wherein the plunger follower is arranged to engage the cam surface to inhibit the rotary sleeve from rotating with respect to the chassis and to inhibit an axial translation of the plunger in the proximal direction in an initial state, wherein, upon release of the engagement of the plunger follower with the cam surface, the rotary sleeve is arranged to rotate within the chassis so that the cam surface re-engages the plunger follower after a time delay determined by a rotation speed of the rotary sleeve, the time delay being set to allow the cam surface to re-engage the plunger follower after the plunger reaches the proximal position, and wherein the cam surface is arranged to withdraw the plunger from the proximal position in a distal direction by continued rotation of the rotary sleeve.