Injection device

An injection device for selecting and dispensing a number of user variable doses of a liquid drug or medicament formulation, the injection device comprising:

• a housing defining an internal space with an inner surface, the inner surface being provided with a thread feature and multiple distinct ratchet features spread along a helical path;
• a dose indicator positioned within the internal space of the housing, the dose indicator having an external surface configured to mesh or engage with the thread feature for restricting a motional freedom of the dose indicator within the housing to follow a helical or screwing movement during a dose dialing and a dose dispensing, the dose indicator further comprising a number of engaging members, at least one of the engaging members being configured to contact the multiple distinct ratchet features in distinct positions during the helical or screwing movement, wherein the contact is configured to provide a user with a tactile feedback by increasing or decreasing a dwelling torque at each of the distinct positions, and wherein the engaging members are resiliently biased towards a distant position;
• a release mechanism connected to the dose indicator, the release mechanism being configured to, when activated during the dose dispensing, urge the engaging members away from the distant position and against a force of the resilient bias thereby suspending the tactile feedback at least for a subset of the multiple distinct positions, wherein the release mechanism comprises a drive member, the drive member being located within the dose indicator and comprising a first sleeve-like element that is axially displaceable relative to the dose indicator during the dose dispensing;
• wherein during the dose dispensing, the dose indicator is rotatably fixed with regard to the first sleeve-like element;
• wherein the drive member comprises a second sleeve-like element positioned within the first sleeve-like element, wherein the second sleeve-like element is splined to a lead screw, the lead screw rotatably coupled with the housing during the dose dispensing and is axially and rotatably fixed with regard to the housing during the dose dialing;
• wherein the first sleeve-like element is coupled to the second sleeve-like element by a connection comprising a pin and groove, wherein the pin moves along the groove during the dose dialing and the dose dispensing;
• and
• wherein the groove provides a first pitch along a first section of the groove and a second pitch along a second section of the groove, wherein the first pitch is different from the second pitch.

An injection device for selecting and dispensing a number of user variable doses of a liquid drug or medicament formulation, the injection device comprising:

• a housing defining an internal space with an inner surface, the inner surface being provided with a thread feature and multiple distinct ratchet features spread along a helical path;
• a dose indicator positioned within the internal space of the housing, the dose indicator having an external surface configured to mesh or engage with the thread feature for restricting a motional freedom of the dose indicator within the housing to follow a helical or screwing movement during a dose dialing and a dose dispensing, the dose indicator further comprising a number of engaging members, at least one of the engaging members being configured to contact the multiple distinct ratchet features in distinct positions during the helical or screwing movement, wherein the contact is configured to provide a user with a tactile feedback by increasing or decreasing a dwelling torque at each of the distinct positions, and wherein the engaging members are resiliently biased towards a distant position;
• a release mechanism connected to the dose indicator, the release mechanism being configured to, when activated during the dose dispensing, urge the engaging members away from the distant position and against a force of the resilient bias thereby suspending the tactile feedback at least for a subset of the multiple distinct positions;
• wherein the release mechanism comprises a drive member, the drive member being located within the dose indicator and comprising a first sleeve-like element that is axially displaceable relative to the dose indicator during the dose dispensing;
• and
• wherein at least one of the engaging members has a wing-like form, and wherein a sloping surface at a proximal end of the wing-like form is adapted such that a corresponding sloping surface at a distal end of the first sleeve-like element engages the sloping surface of the wing-like form during the dose dispensing and after an axial displacement of the first sleeve-like element thereby urging the engaging member away from the distant position.