EP2364740A1 — Arrangement for transferring a translation of a drive means to a plunger

USPTO Abstract

The invention relates to an arrangement for transferring a translation of a drive means (8) to a plunger (9) arranged for pushing against a stopper (6) for sealing a syringe (3) and displacing a medicament (M) stored in the syringe (3), the arrangement comprising an elongate release latch member (22) pivoted at one end which is connected to either the drive means (8) or the plunger (9), the release latch member (22) having another end for engaging the respective other one of the drive means (8) or the plunger (9), wherein the release latch member (22) is arranged to have its non-pivoted other end disengaged by rotation due to contact between at least one ramp (15.2, 22.1) and another component when the stopper (6) has at least nearly displaced all of a predefined dose of the medicament (M), wherein a length of the release latch member (22) is specified so as to provide a clearance between the plunger (9) and the drive means (8) when the release latch member (22) is disengaged in order to allow the plunger (9), the stopper (6) and a hollow needle (4) of the syringe (3) to be retracted at least far enough to hide the needle (4) inside the syringe (3) after disengaging the release latch member (22).