Patent ID: 9352090
Filing Date: 2016-05-31
CPC Classification: A61M

Claim Text:
1. An auto-injector for administering a dose of a liquid medicament, comprising: a tubular chassis, a carrier subassembly comprising a tubular carrier slidably arranged partially inside the chassis, the carrier adapted to contain a syringe with a hollow injection needle, a drive spring and a plunger for forwarding load of the drive spring to a stopper of the syringe, wherein the syringe is lockable for joint axial translation with the carrier, a control spring arranged around the carrier, a needle insertion control mechanism for coupling a proximal end of the control spring to either the carrier for advancing it for needle insertion or to the chassis for needle retraction depending on the relative axial position of the carrier and the chassis, wherein the needle insertion control mechanism comprises a first collar biased by the control spring in a proximal direction, wherein at least one resilient beam is proximally arranged on the first collar, wherein respective recesses are arranged in the carrier and chassis, wherein a transversal extension of a head of the resilient beam is wider than a gap between the carrier and the chassis causing the head of the resilient beam to abut a distal face on the recess in the chassis while being prevented from deflecting in an inward direction by the carrier or to abut a distal face on the recess in the carrier while being prevented from deflecting in an outward direction by the chassis thereby forwarding load from the control spring to the carrier for needle insertion, wherein the resilient beam is arranged to be switched between the chassis and the carrier by ramped engagement of the head to the distal faces under load of the control spring depending on the relative longitudinal position between the chassis and the carrier.