Activation assembly for a medicament delivery device

An activation assembly for a medicament delivery device, wherein the activation assembly comprises:

• a delivery member cover comprising a distally extending leg having a cam surface;
• a movable sleeve comprising a distal facing stop surface, where the movable sleeve and the stop surface rotate from an initial position to an activation position as the cam surface of the delivery member cover engages the movable sleeve and moves axially in a distal direction;
• and
• an activation sleeve that moves axially relative to the movable sleeve to activate the medicament delivery device, where the activation sleeve comprises a proximally directed leg that will engage the stop surface when the moveable sleeve is in the initial position to prevent axial movement of the activation sleeve relative to the delivery member cover and to prevent actuation of the activation assembly,
• wherein when the movable sleeve moves to the activation position from the initial position, the activation sleeve is no longer blocked from moving axially relative to the movable sleeve,
• wherein when the delivery member cover moves axially in the distal direction relative to the movable sleeve the cam surface slidably engages the movable sleeve causing the movable sleeve to rotate to the activation position thereby allowing actuation of the activation assembly.

A method of activating an auto-injector comprising:

• providing an activation assembly comprising a delivery member cover, a movable sleeve, and an activation sleeve, where the activation assembly is contained within a housing of the auto-injector;
• preventing actuation of the auto-injector by axial alignment of a distal facing stop surface on the moveable sleeve with a proximally directed leg of the actuation sleeve such that the activation sleeve is blocked from moving axially relative to the movable sleeve to activate the medicament delivery device;
• placing a proximal end of the delivery member cover against an injection site and pushing the housing towards the injection site to cause the delivery member cover to retract inside of the housing and to move a distally extending leg of the delivery member cover having a first cam surface relative to the movable sleeve;
• and
• slidably engaging the first cam surface with a second cam surface located on the movable sleeve, thereby rotating the movable sleeve from an initial position to an activation position,
• wherein rotation of the movable sleeve moves the stop surface out of alignment with the proximally directed leg of the actuation sleeve such that the activation sleeve is no longer blocked from moving axially relative to the movable sleeve, thereby allowing the activation sleeve to move axially and activating the auto-injector.