Dose setting mechanism and injection device

摘要

A dose setting mechanism comprising a dose setting member and a drive member for driving a piston rod in a distal direction during dose dispensing. The drive member comprises a proximal drive member and a distal drive member. A first clutch releasably coupling the proximal drive member and the distal drive member. A spring means biases the proximal drive member and the distal drive member in the coupled state during dose setting and dose dispensing. Engaging means are provided associated to the proximal drive member and to the dose setting member, wherein the engaging means are designed and arranged such that the proximal drive member entrains the dose setting member in the distal direction during dose setting but allows a relative axial movement of the proximal drive member with respect to the dose setting member in the proximal direction.

主权项

1. A dose setting mechanism for a drug delivery device, the mechanism comprising:
a dose setting member, a drive member, for driving a piston rod in a distal direction during dose dispensing, the drive member comprising a proximal drive member and a distal drive member, a first clutch for releasably coupling the proximal drive member and the distal drive member, spring means for biasing the proximal drive member and the distal drive member in the coupled state during dose setting and dose dispensing, and engaging means associated to the proximal drive member and to the dose setting member, characterized in that the engaging means comprises hooks provided on fingers protruding from the proximal end of the proximal drive member and a corresponding inwardly protruding flange on the proximal end of the dose setting member such that the proximal drive member entrains the dose setting member in the distal direction during dose dispensing but allows a relative axial movement of the proximal drive member with respect to the dose setting member in a proximal direction.