Autoinjector for automatic injection of a product into an injection site

Abstract

The autoinjector includes a housing extending along a longitudinal axis A and configured to receive a medical container having a barrel defining a reservoir for containing a medical product. The barrel having a distal end provided with an injection needle and an opened proximal end configured to receive a plunger rod for pushing a stopper arranged inside the barrel. A needle cover is coupled to and axially movable with respect to said housing between a first extended position, a retracted position, and a second extended position. A plunger rod is axially movable inside the housing between a storage position and an injection end position, the plunger rod being configured to push the stopper in order to expel the medical product. The autoinjector also includes biasing means for biasing the plunger rod in a distal direction towards the injection end position, a retainer for maintaining the plunger rod in the initial position against the action of the biasing means, the retainer including a blocking member radially movable between a blocking position for blocking the plunger rod in the initial position, and a release position allowing for movement of the plunger rod in the distal direction. A first locker is axially movable with respect to the retainer between a locking position for maintaining the blocking member in the blocking position, and a release position, axial movement of the first locker from the locking position to the release position being caused by the needle cover moving from the first extended position to the retracted position. A second locker, is rotationally movable around the longitudinal axis A with respect to said housing, between a locking position for preventing axial movement of the first locker from the locking position to the release position, and a release position for allowing axial movement of the first locker from the locking position to the release position. The autoinjector further includes axial securing means for axially securing the second locker with respect to the housing.