Actuator device, especially for an injection device

Actuator means (2, 10), in particular for an injection device, comprising - a in an axial direction extended housing (3), - a is positioned axially on one side fastened to a fastening side of actuator element (5, 11) with a predetermined axial starting length (L) of a FSMA (Ferromagnetic Shape Memory Alloy) material, - a nozzle or valve member (7) with the actuator element (5, 11) on which the fastening side axially opposite movable side, and via which a supply of a medium is set in a working volume, and - means to a repeatable change in the axial length of the actuator element (5, 11) of FSMA material to a predetermined axial length change (.DELTA.L), said means a) expansion means for adjusting the axial change in length (.DELTA.L) and, separately, b) resetting means for resetting the (by change in length .DELTA.L) amended axial length (L + .DELTA.L) (to the initial length L) comprise, - wherein the elongation means through a (on the actuator element 5, ...