Connection mechanism for an auxiliary module

An auxiliary module for connecting to an injector for dispensing a medical substance, the auxiliary module comprising:

• a housing with a longitudinal axis extending between a proximal end and a distal end of the housing, the housing defining a housing interior with a closed proximal end and an open distal end;
• a retainer comprising a sleeve-shaped insert arranged within the housing interior;
• and
• a receiving unit with a retaining element, wherein the receiving unit is sleeve-shaped, a half shell or a plate with a circumferential wall forming a cavity configured for accommodating the injector, and the receiving unit is movable linearly along the longitudinal axis relative to the housing,
• wherein:
• a. the auxiliary module has a retaining configuration, in which the receiving unit is retained in the housing by the retainer and in which the retaining element forms an engagement with the injector such that the injector is retained by the receiving unit;
• and
• b. the auxiliary module has a release configuration, in which the receiving unit is released from the retainer and the injector is released from the engagement with the retaining element,
• wherein the auxiliary module is adjustable from the retaining configuration into the release configuration, and back again, by an adjustment movement of the receiving unit along the longitudinal axis, and
• wherein the insert comprises ribs engaged in grooves of the housing interior such that the insert is non-movable relative to the housing during the adjustment movement.