Cartridge fixation for a drug delivery device

A cartridge unit for a drug delivery device, the cartridge unit comprising:

• a housing, the housing comprising:
• a recess for accommodating a proximal portion of a cartridge containing a liquid drug, the recess having an axis defining a longitudinal direction;
• and
• a deformable member arranged inside of the recess, wherein the deformable member is formed in one piece and comprises a proximal end attached to the housing and a distal end movable within the recess relative to the housing,
• wherein the deformable member is deformable from a non-deformed state to a deformed state by a displacement of the distal end, wherein in the deformed state the deformable member is configured to limit a movement of the cartridge arranged in the recess in the longitudinal direction relative to the housing, and
• wherein the deformable member comprises an arch, and in the deformed state the arch is deformed both elastically and plastically by the cartridge;
• and
• a cartridge holder for accommodating a distal portion of the cartridge and connectable to a distal end of the housing such that the cartridge is held relative to the housing by the cartridge holder and the housing,
• wherein in the deformed state a proximal end of the cartridge abuts the distal end of the deformable member.

A method for assembling a cartridge unit for a drug delivery device, comprising the steps of:

• obtaining a housing, the housing comprising a recess for accommodating a proximal portion of the cartridge, the recess having an axis defining a longitudinal direction, a deformable member being arranged inside the recess, wherein the deformable member is formed in one piece and includes a proximal end attached to the housing and a distal end movable within the recess relative to the housing, the deformable member further comprising an arch;
• inserting a distal portion of the cartridge into an opening of a sleeve-shaped cartridge holder;
• inserting a proximal end portion of the cartridge holder containing the cartridge into the recess of the housing in the longitudinal direction;
• deforming, using a proximal end of the cartridge, the deformable member of the housing from a non-deformed state to a deformed state by a displacement of a distal end of the deformable member in the proximal and longitudinal direction to thereby deform the arch both elastically and plastically;
• and
• connecting the proximal end portion of the cartridge holder with a distal end portion of the housing.