A safety device(1) for a pre-filled syringe (2) is proposed that comprises -a hollow support body (1.2) with a helical groove (1.2.2) formed into an inner surface thereof, -a mounting collar (1.4) for mounting the pre-filled syringe (2) to the support body (1.2), -a spinning collar (1.5) with a helical tongue (1.5.2) formed to an outer surface thereof and -a torsion spring(1.6). The helical groove (1.2.2) accommodates the helical tongue (1.5.2). Upon release, the torsion spring (1.6) is capable of exerting a torque upon the spinning collar (1.5) which causes the spinning collar(1.5) to rotate within the support body(1.2). The engagement of the helical groove (1.2.2) and the helical tongue (1.5.2) redirects the rotational movement of the spinning collar (1.5) to a translatory movement that moves the mounting collar (1.4) in a proximal direction.
