| abstract |
The invention relates to an auto-injector (1) with a delay mechanism (36) for slowing down motion of a retraction sleeve (10) in axial direction of the auto-injector (1), the delay mechanism (36) comprising a circumferential outer wall (37) with a back collar (38) attached to a housing (2) of the auto-injector (1) and a circumferential inner wall (39) with a front collar (40) attached to the retraction sleeve (10) wherein a cavity is defined between the outer wall (37) and inner wall (39), the cavity sealed by the back collar (38) against the inner wall (39) and by the front collar (40) against the outer wall (37), the cavity filled with a viscous fluid, wherein at least one orifice is arranged in the delay mechanism (36) for allowing the viscous fluid to be pushed out as the volume of the cavity decreases due to axial motion of the component with respect to the housing. The retraction sleeve (10) is axially movably arranged in the housing (2) and serves for retracting the syringe (3) with the needle (4) into the covered position after delivering the medicament (M). |