An advantageous device (1) for moving the piston inside a cartridge has a cartridge body (2) and a piston (3) arranged therein displaceable along a longitudinal axis (Z) of the cartridge body (2), and comprises: a first portion (4) having first coupling means (5) for releasably coupling the cartridge body (2) of the cartridge to the first portion (4) in such a manner that in both directions of said longitudinal axis (Z) of the cartridge body (2) there exists a positive connection and/or a frictional connection between the cartridge body (2) and the first portion (4) and a second portion (6) having second coupling means (7, 11a, 11b, 12 7, 12, 17a, 17b) for releasably coupling the piston (3) of the cartridge to the second portion (6) in such a manner that in both directions of said longitudinal axis (Z) of the cartridge body (2) there exists a positive connection and/or a frictional connection between the piston (3) and the second portion (6). Said first (4) and second portions (6) are moveable relative to each other in order to effect, in the intended use of the device (1), at least a forward displacement of the piston (3) coupled to the second portion (6) inside the cartridge body (2) coupled to the first portion (4) along said longitudinal axis (Z) of the cartridge body (2). The second coupling means (7, 11 a, 11 b, 12 7, 12, 17a, 17b) are designed in such a manner that for establishing and releasing the positive connection and/or frictional connection with the piston (3), their shape can reversibly be changed.Linvention porte sur un dispositif avantageux (1) pour déplacer un piston dans une cartouche, ce dispositif possédant un corps de cartouche (2) et un piston (3) agencé dans ce corps et pouvant être déplacé selon un axe longitudinal (Z) du corps de cartouche (2). Le dispositif comprend : une première partie (4) ayant des premiers moyens daccouplement (5) servant à accoupler le corps de cartouche (2) à la première partie (4) de façon libérable, de telle sorte
