Patent ID: 8353878
Filing Date: 2013-01-15
Classification: A61M

Abstract:
1. An injection device for injecting a dose of drug, the injection device comprising: a housing, a dose setting mechanism being operable to set a desired dose, the dose setting mechanism comprising a rotatable dose knob, operation of the dose setting mechanism causing energy to be stored in a spring member, an injection mechanism comprising a piston rod adapted to cooperate with a piston positioned in a cartridge containing a drug to be delivered in order to cause a set dose to be delivered from the cartridge via the injection device, the injection mechanism being driven by releasing energy previously stored in the spring member during dose setting, a dosage tube being axially movable in a proximal direction relatively to the housing during dose setting and being axially movable in a distal direction relatively to the housing during injection of a set dose, and retaining means is a locking nut being axially fixed relatively to the housing, said locking nut being adapted to be rotationally locked relatively to the housing during dose setting, and adapted to be able to perform rotational movement relatively to the housing during injection of a set dose, the retaining means arranged to prevent axial movement of the dosage tube in a distal direction relatively to the housing during dose setting.