Assembly for a cartridge needle insertion mechanism

An assembly for a cartridge needle insertion mechanism, comprising:

• a housing;
• a cartridge needle defining a cartridge needle axis;
• a cartridge closed by a septum;
• a cartridge needle slider linearly guidable by the housing along an insertion axis and movable by a driver from a first position in which the cartridge needle is not penetrating the septum to a second position in which the cartridge needle penetrates the septum;
• a cartridge needle holder holding the cartridge needle, the cartridge needle holder operatively coupled with the cartridge needle slider such that movement of the cartridge needle slider carries the cartridge needle holder along the insertion axis from the first position to the second position to thereby cause the cartridge needle to penetrate the septum;
• and
• a compliant coupling comprising a first coupling member on the cartridge needle holder and a second coupling member on the cartridge needle slider,
• wherein the first coupling member comprises a protrusion radially extending from the cartridge needle holder, whereby the protrusion is at least partially elastically and/or plastically deformable and engages the second coupling member shaped as a rigid surface on the cartridge needle slider being oriented parallel to the insertion axis, or wherein the first coupling member comprises a rigid protrusion radially extending from the cartridge needle holder engaging the second coupling member shaped as an at least partially elastically and/or plastically deformable surface on the cartridge needle slider being oriented parallel to the insertion axis,
• wherein the first coupling member and the second coupling member are configured to elastically engage and/or configured to engage in a linear or rotational friction fit engagement in a plane parallel to the insertion axis, and
• wherein the compliant coupling is configured to facilitate a movement of the cartridge needle holder with respect to the cartridge needle slider when moved into the second position, thereby compensating for needle penetration forces that are oriented perpendicular to the insertion axis.