Abstract: The present invention relates to an injection device for automatic torsion spring driven injection of a liquid drug. The injection device is of the type wherein a telescopically movable needle shield (20) activates the release of the torque of the torsion spring to drive the injection when the needle shield is moved from its extended position to a retracted position. The injection device is provided with a needle interface (30) carrying the injection needle, which needle interface is provided with means (32) preventing axial movement of the shield when no injection needle is mounted. Further, other means are provided to restrain the needle shield in the retracted position when the injection device is its “zero” position such that a user has access to the injection needle in order to exchange the injection needle.

Abstract: The invention relates to a torsion spring driven injection device having a dial-down mechanism for dialling down a selected dose size. The torsion spring (2) is strained when setting a dose by rotating a proximally located dose setting button(30) relatively to the housing in a first direction and unstained when rotating the same dose setting button (30) in a second direction opposite the first direction. In order to secure the torsion spring (2) in its strained position a one-way ratchet mechanism is provided. This one-way ratchet mechanism comprises a fixation element (1) coupled to the housing and having a toothing (6) and a ratchet element (20) having at least one ratchet arm (22) engaging the fixation element (1) and which ratchet element (20) is operational coupled to the dose setting button (30).

Abstract: The present invention relates to medicament injection devices (100). A cartridge (600) with a septum and a needle unit (500) having front and rear needles (510, 520) are configured for relative movement from a state where the septum is sealed to a state where the septum is pierced by the rear needle (520). The injection device (100) may include a needle shield (350) and be configured for piercing the septum by the rear needle (520) when the front needle (510) is operated relative to the needle shield (350). The injection device (100) may also include a damping mechanism configured for limiting the speed of movement of the cartridge relative to the needle unit. The injection device (100) may also include an indicator generating a signal when a piston driver has travelled the complete stroke length, wherein the indicator has a deflection element that is deflected prior to or during movement of the cartridge relative to the housing.